diff --git a/README.md b/README.md
index dd6c13556a1b..8466dc953aa3 100644
--- a/README.md
+++ b/README.md
@@ -145,7 +145,6 @@ Complete source code can be found at
 
 ```java
 import com.google.cloud.bigquery.BigQuery;
-import com.google.cloud.bigquery.BigQueryError;
 import com.google.cloud.bigquery.BigQueryOptions;
 import com.google.cloud.bigquery.Field;
 import com.google.cloud.bigquery.FormatOptions;
@@ -156,8 +155,6 @@ import com.google.cloud.bigquery.Table;
 import com.google.cloud.bigquery.TableId;
 import com.google.cloud.bigquery.TableInfo;
 
-import java.util.List;
-
 BigQuery bigquery = BigQueryOptions.defaultInstance().service();
 TableId tableId = TableId.of("dataset", "table");
 Table table = bigquery.getTable(tableId);
@@ -169,17 +166,12 @@ if (table == null) {
 }
 System.out.println("Loading data into table " + tableId);
 Job loadJob = table.load(FormatOptions.csv(), "gs://bucket/path");
-loadJob.whenDone(new Job.CompletionCallback() {
-  @Override
-  public void success(Job job) {
-    System.out.println("Job succeeded");
-  }
-
-  @Override
-  public void error(BigQueryError error, List<BigQueryError> executionErrors) {
-    System.out.println("Job completed with errors");
-  }
-});
+loadJob = loadJob.waitFor();
+if (loadJob.status().error() != null) {
+  System.out.println("Job completed with errors");
+} else {
+  System.out.println("Job succeeded");
+}
 ```
 
 Google Cloud Compute (Alpha)
@@ -202,31 +194,19 @@ import com.google.cloud.compute.Compute;
 import com.google.cloud.compute.ComputeOptions;
 import com.google.cloud.compute.Disk;
 import com.google.cloud.compute.DiskId;
-import com.google.cloud.compute.Operation.OperationError;
-import com.google.cloud.compute.Operation.OperationWarning;
 import com.google.cloud.compute.Snapshot;
 
-import java.util.List;
-
 final Compute compute = ComputeOptions.defaultInstance().service();
 DiskId diskId = DiskId.of("us-central1-a", "disk-name");
 Disk disk = compute.getDisk(diskId, Compute.DiskOption.fields());
 if (disk != null) {
   final String snapshotName = "disk-name-snapshot";
   Operation operation = disk.createSnapshot(snapshotName);
-  operation.whenDone(new Operation.CompletionCallback() {
-    @Override
-    public void success(Operation operation) {
-      // use snapshot
-      Snapshot snapshot = compute.getSnapshot(snapshotName);
-    }
-
-    @Override
-    public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-      // inspect errors
-      throw new RuntimeException("Snaphsot creation failed");
-    }
-  });
+  operation = operation.waitFor();
+  if (operation.errors() == null) {
+    // use snapshot
+    Snapshot snapshot = compute.getSnapshot(snapshotName);
+  }
 }
 ```
 The second snippet shows how to create a virtual machine instance. Complete source code can be found
@@ -242,10 +222,6 @@ import com.google.cloud.compute.InstanceId;
 import com.google.cloud.compute.InstanceInfo;
 import com.google.cloud.compute.MachineTypeId;
 import com.google.cloud.compute.NetworkId;
-import com.google.cloud.compute.Operation.OperationError;
-import com.google.cloud.compute.Operation.OperationWarning;
-
-import java.util.List;
 
 Compute compute = ComputeOptions.defaultInstance().service();
 ImageId imageId = ImageId.of("debian-cloud", "debian-8-jessie-v20160329");
@@ -256,9 +232,7 @@ InstanceId instanceId = InstanceId.of("us-central1-a", "instance-name");
 MachineTypeId machineTypeId = MachineTypeId.of("us-central1-a", "n1-standard-1");
 Operation operation =
     compute.create(InstanceInfo.of(instanceId, machineTypeId, attachedDisk, networkInterface));
-while (!operation.isDone()) {
-  Thread.sleep(1000L);
-}
+operation = operation.waitFor();
 if (operation.errors() == null) {
   // use instance
   Instance instance = compute.getInstance(instanceId);
diff --git a/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/Job.java b/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/Job.java
index caea0ee38390..0089bff21dd7 100644
--- a/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/Job.java
+++ b/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/Job.java
@@ -20,8 +20,8 @@
 
 import java.io.IOException;
 import java.io.ObjectInputStream;
-import java.util.List;
 import java.util.Objects;
+import java.util.concurrent.TimeUnit;
 
 /**
  * A Google BigQuery Job.
@@ -38,24 +38,6 @@ public class Job extends JobInfo {
   private final BigQueryOptions options;
   private transient BigQuery bigquery;
 
-  /**
-   * A callback for job completion.
-   */
-  public interface CompletionCallback {
-    /**
-     * The method called when the job completes successfully.
-     */
-    void success(Job job);
-
-    /**
-     * The method called when the job completes with errors. {@code error} is the final error that
-     * caused the job to fail (see {@link JobStatus#error()}). {@code executionErrors} are all the
-     * errors (possibly not fatal) encountered by the job during its execution (see
-     * {@link JobStatus#executionErrors()}).
-     */
-    void error(BigQueryError error, List<BigQueryError> executionErrors);
-  }
-
   /**
    * A builder for {@code Job} objects.
    */
@@ -163,40 +145,51 @@ public boolean isDone() {
   }
 
   /**
-   * Waits until this job completes its execution, either failing or succeeding. If the job does not
-   * exist, this method returns without executing any method of the provided callback. If the job
-   * completed successfully the {@link CompletionCallback#success(Job)} method is called. If the job
-   * completed with errors the {@link CompletionCallback#error(BigQueryError, List)} method is
-   * called.
+   * Blocks until this job completes its execution, either failing or succeeding. The job status is
+   * checked every 500 milliseconds. This method returns current job's latest information. If the
+   * job no longer exists, this method returns {@code null}.
    * <pre> {@code
-   * job.whenDone(new CompletionCallback() {
-   *   void success(Job job) {
-   *     // completed successfully
-   *   }
+   * Job completedJob = job.waitFor();
+   * if (completedJob == null) {
+   *   // job no longer exists
+   * } else if (completedJob.status().error() != null) {
+   *   // job failed, handle error
+   * } else {
+   *   // job completed successfully
+   * }}</pre>
    *
-   *   void error(BigQueryError error, List<BigQueryError> executionErrors) {
-   *     // handle error
-   *   }
-   * });}</pre>
+   * @throws BigQueryException upon failure
+   * @throws InterruptedException if the current thread gets interrupted while waiting for the job
+   *     to complete
+   */
+  public Job waitFor() throws InterruptedException {
+    return waitFor(500, TimeUnit.MILLISECONDS);
+  }
+
+  /**
+   * Blocks until this job completes its execution, either failing or succeeding. The
+   * {@code checkEvery} and {@code unit} parameters determine how often the job's status is checked.
+   * This method returns current job's latest information. If the job no longer exists, this method
+   * returns {@code null}.
+   * <pre> {@code
+   * Job completedJob = job.waitFor(1, TimeUnit.SECONDS);
+   * if (completedJob == null) {
+   *   // job no longer exists
+   * } else if (completedJob.status().error() != null) {
+   *   // job failed, handle error
+   * } else {
+   *   // job completed successfully
+   * }}</pre>
    *
    * @throws BigQueryException upon failure
    * @throws InterruptedException if the current thread gets interrupted while waiting for the job
    *     to complete
    */
-  public void whenDone(CompletionCallback callback) throws InterruptedException {
+  public Job waitFor(int checkEvery, TimeUnit unit) throws InterruptedException {
     while (!isDone()) {
-      Thread.sleep(500L);
-    }
-    Job updatedJob = reload();
-    if (updatedJob == null) {
-      return;
-    }
-    BigQueryError error = updatedJob.status().error();
-    if (error != null) {
-      callback.error(error, updatedJob.status().executionErrors());
-    } else {
-      callback.success(updatedJob);
+      unit.sleep(checkEvery);
     }
+    return reload();
   }
 
   /**
diff --git a/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/package-info.java b/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/package-info.java
index 19e1d96fedef..3b4d392d26dc 100644
--- a/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/package-info.java
+++ b/gcloud-java-bigquery/src/main/java/com/google/cloud/bigquery/package-info.java
@@ -33,15 +33,12 @@
  * }
  * System.out.println("Loading data into table " + tableId);
  * Job loadJob = table.load(FormatOptions.csv(), "gs://bucket/path");
- * loadJob.whenDone(new Job.CompletionCallback() {
- *   public void success(Job job) {
- *     System.out.println("Job succeeded");
- *   }
- *
- *   public void error(BigQueryError error, List<BigQueryError> executionErrors) {
- *     System.out.println("Job completed with errors");
- *   }
- * });}</pre>
+ * loadJob = loadJob.waitFor();
+ * if (loadJob.status().error() != null) {
+ *   System.out.println("Job completed with errors");
+ * } else {
+ *   System.out.println("Job succeeded");
+ * }}</pre>
  *
  * @see <a href="https://cloud.google.com/bigquery/">Google Cloud BigQuery</a>
  */
diff --git a/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/JobTest.java b/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/JobTest.java
index 11896baded43..26178054d304 100644
--- a/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/JobTest.java
+++ b/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/JobTest.java
@@ -28,13 +28,12 @@
 import static org.junit.Assert.assertTrue;
 
 import com.google.cloud.bigquery.JobStatistics.CopyStatistics;
-import com.google.common.collect.ImmutableList;
 
 import org.easymock.EasyMock;
 import org.junit.After;
 import org.junit.Test;
 
-import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 public class JobTest {
 
@@ -182,60 +181,71 @@ public void testIsDone_NotExists() throws Exception {
   }
 
   @Test
-  public void testWhenDone_Success() throws InterruptedException {
+  public void testWaitFor() throws InterruptedException {
     initializeExpectedJob(2);
-    Job.CompletionCallback callback = EasyMock.mock(Job.CompletionCallback.class);
     BigQuery.JobOption[] expectedOptions = {BigQuery.JobOption.fields(BigQuery.JobField.STATUS)};
     JobStatus status = createStrictMock(JobStatus.class);
     expect(status.state()).andReturn(JobStatus.State.DONE);
-    expect(status.error()).andReturn(null);
     expect(bigquery.options()).andReturn(mockOptions);
     Job completedJob = expectedJob.toBuilder().status(status).build();
     expect(bigquery.getJob(JOB_INFO.jobId(), expectedOptions)).andReturn(completedJob);
     expect(bigquery.getJob(JOB_INFO.jobId())).andReturn(completedJob);
-    callback.success(completedJob);
-    EasyMock.expectLastCall();
-    replay(status, bigquery, callback);
+    replay(status, bigquery);
     initializeJob();
-    job.whenDone(callback);
-    verify(status, callback);
+    assertSame(completedJob, job.waitFor());
+    verify(status);
   }
 
   @Test
-  public void testWhenDone_Error() throws InterruptedException {
-    initializeExpectedJob(2);
-    Job.CompletionCallback callback = EasyMock.mock(Job.CompletionCallback.class);
+  public void testWaitFor_Null() throws InterruptedException {
+    initializeExpectedJob(1);
+    BigQuery.JobOption[] expectedOptions = {BigQuery.JobOption.fields(BigQuery.JobField.STATUS)};
+    expect(bigquery.options()).andReturn(mockOptions);
+    expect(bigquery.getJob(JOB_INFO.jobId(), expectedOptions)).andReturn(null);
+    expect(bigquery.getJob(JOB_INFO.jobId())).andReturn(null);
+    replay(bigquery);
+    initializeJob();
+    assertNull(job.waitFor());
+  }
+
+  @Test
+  public void testWaitForWithTimeUnit() throws InterruptedException {
+    initializeExpectedJob(3);
     BigQuery.JobOption[] expectedOptions = {BigQuery.JobOption.fields(BigQuery.JobField.STATUS)};
-    BigQueryError error = new BigQueryError("reason", "location", "message");
-    List<BigQueryError> executionErrors = ImmutableList.of(error);
+    TimeUnit timeUnit = createStrictMock(TimeUnit.class);
+    timeUnit.sleep(42);
+    EasyMock.expectLastCall();
     JobStatus status = createStrictMock(JobStatus.class);
+    expect(status.state()).andReturn(JobStatus.State.RUNNING);
     expect(status.state()).andReturn(JobStatus.State.DONE);
-    expect(status.error()).andReturn(error);
-    expect(status.executionErrors()).andReturn(executionErrors);
     expect(bigquery.options()).andReturn(mockOptions);
+    Job runningJob = expectedJob.toBuilder().status(status).build();
     Job completedJob = expectedJob.toBuilder().status(status).build();
+    expect(bigquery.getJob(JOB_INFO.jobId(), expectedOptions)).andReturn(runningJob);
     expect(bigquery.getJob(JOB_INFO.jobId(), expectedOptions)).andReturn(completedJob);
     expect(bigquery.getJob(JOB_INFO.jobId())).andReturn(completedJob);
-    callback.error(error, executionErrors);
-    EasyMock.expectLastCall();
-    replay(status, bigquery, callback);
+    replay(status, bigquery, timeUnit);
     initializeJob();
-    job.whenDone(callback);
-    verify(status, callback);
+    assertSame(completedJob, job.waitFor(42, timeUnit));
+    verify(status, timeUnit);
   }
 
   @Test
-  public void testWhenDone_Null() throws InterruptedException {
-    initializeExpectedJob(1);
-    Job.CompletionCallback callback = EasyMock.mock(Job.CompletionCallback.class);
+  public void testWaitForWithTimeUnit_Null() throws InterruptedException {
+    initializeExpectedJob(2);
     BigQuery.JobOption[] expectedOptions = {BigQuery.JobOption.fields(BigQuery.JobField.STATUS)};
+    TimeUnit timeUnit = createStrictMock(TimeUnit.class);
+    timeUnit.sleep(42);
+    EasyMock.expectLastCall();
     expect(bigquery.options()).andReturn(mockOptions);
+    Job runningJob = expectedJob.toBuilder().status(new JobStatus(JobStatus.State.RUNNING)).build();
+    expect(bigquery.getJob(JOB_INFO.jobId(), expectedOptions)).andReturn(runningJob);
     expect(bigquery.getJob(JOB_INFO.jobId(), expectedOptions)).andReturn(null);
     expect(bigquery.getJob(JOB_INFO.jobId())).andReturn(null);
-    replay(bigquery, callback);
+    replay(bigquery, timeUnit);
     initializeJob();
-    job.whenDone(callback);
-    verify(callback);
+    assertNull(job.waitFor(42, timeUnit));
+    verify(bigquery, timeUnit);
   }
 
   @Test
diff --git a/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/it/ITBigQueryTest.java b/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/it/ITBigQueryTest.java
index 444b25add682..eb3b8c9c5597 100644
--- a/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/it/ITBigQueryTest.java
+++ b/gcloud-java-bigquery/src/test/java/com/google/cloud/bigquery/it/ITBigQueryTest.java
@@ -188,11 +188,8 @@ public static void beforeClass() throws InterruptedException {
         .schema(TABLE_SCHEMA)
         .build();
     Job job = bigquery.create(JobInfo.of(configuration));
-    Job.CompletionCallback callback = EasyMock.createStrictMock(Job.CompletionCallback.class);
-    callback.success(EasyMock.<Job>anyObject());
-    EasyMock.replay(callback);
-    job.whenDone(callback);
-    EasyMock.verify(callback);
+    job = job.waitFor();
+    assertNull(job.status().error());
   }
 
   @AfterClass
@@ -800,11 +797,8 @@ public void testCopyJob() throws InterruptedException {
     TableId destinationTable = TableId.of(DATASET, destinationTableName);
     CopyJobConfiguration configuration = CopyJobConfiguration.of(destinationTable, sourceTable);
     Job remoteJob = bigquery.create(JobInfo.of(configuration));
-    Job.CompletionCallback callback = EasyMock.createStrictMock(Job.CompletionCallback.class);
-    callback.success(EasyMock.<Job>anyObject());
-    EasyMock.replay(callback);
-    remoteJob.whenDone(callback);
-    EasyMock.verify(callback);
+    remoteJob = remoteJob.waitFor();
+    assertNull(remoteJob.status().error());
     Table remoteTable = bigquery.getTable(DATASET, destinationTableName);
     assertNotNull(remoteTable);
     assertEquals(destinationTable.dataset(), remoteTable.tableId().dataset());
@@ -827,11 +821,8 @@ public void testQueryJob() throws InterruptedException {
         .destinationTable(destinationTable)
         .build();
     Job remoteJob = bigquery.create(JobInfo.of(configuration));
-    Job.CompletionCallback callback = EasyMock.createStrictMock(Job.CompletionCallback.class);
-    callback.success(EasyMock.<Job>anyObject());
-    EasyMock.replay(callback);
-    remoteJob.whenDone(callback);
-    EasyMock.reset(callback);
+    remoteJob = remoteJob.waitFor();
+    assertNull(remoteJob.status().error());
 
     QueryResponse response = bigquery.getQueryResults(remoteJob.jobId());
     while (!response.jobCompleted()) {
@@ -869,21 +860,16 @@ public void testExtractJob() throws InterruptedException {
             .schema(SIMPLE_SCHEMA)
             .build();
     Job remoteLoadJob = bigquery.create(JobInfo.of(configuration));
-    Job.CompletionCallback callback = EasyMock.createStrictMock(Job.CompletionCallback.class);
-    callback.success(EasyMock.<Job>anyObject());
-    EasyMock.replay(callback);
-    remoteLoadJob.whenDone(callback);
-    EasyMock.reset(callback);
+    remoteLoadJob = remoteLoadJob.waitFor();
+    assertNull(remoteLoadJob.status().error());
 
     ExtractJobConfiguration extractConfiguration =
         ExtractJobConfiguration.builder(destinationTable, "gs://" + BUCKET + "/" + EXTRACT_FILE)
             .printHeader(false)
             .build();
     Job remoteExtractJob = bigquery.create(JobInfo.of(extractConfiguration));
-    callback.success(EasyMock.<Job>anyObject());
-    EasyMock.replay(callback);
-    remoteExtractJob.whenDone(callback);
-    EasyMock.verify(callback);
+    remoteExtractJob = remoteExtractJob.waitFor();
+    assertNull(remoteExtractJob.status().error());
     assertEquals(CSV_CONTENT,
         new String(storage.readAllBytes(BUCKET, EXTRACT_FILE), StandardCharsets.UTF_8));
     assertTrue(bigquery.delete(DATASET, tableName));
@@ -900,11 +886,8 @@ public void testCancelJob() throws InterruptedException {
         .build();
     Job remoteJob = bigquery.create(JobInfo.of(configuration));
     assertTrue(remoteJob.cancel());
-    Job.CompletionCallback callback = EasyMock.createStrictMock(Job.CompletionCallback.class);
-    callback.success(EasyMock.<Job>anyObject());
-    EasyMock.replay(callback);
-    remoteJob.whenDone(callback);
-    EasyMock.verify(callback);
+    remoteJob = remoteJob.waitFor();
+    assertNull(remoteJob.status().error());
   }
 
   @Test
diff --git a/gcloud-java-compute/README.md b/gcloud-java-compute/README.md
index 49e692da84c2..81d48759221d 100644
--- a/gcloud-java-compute/README.md
+++ b/gcloud-java-compute/README.md
@@ -104,11 +104,7 @@ Add the following imports at the top of your file:
 ```java
 import com.google.cloud.compute.AddressInfo;
 import com.google.cloud.compute.Operation;
-import com.google.cloud.compute.Operation.OperationError;
-import com.google.cloud.compute.Operation.OperationWarning;
 import com.google.cloud.compute.RegionAddressId;
-
-import java.util.List;
 ```
 
 Then add the following code to create an address. Most Compute Engine calls return an `Operation`
@@ -119,18 +115,13 @@ succeeded:
 final RegionAddressId addressId = RegionAddressId.of("us-central1", "test-address");
 Operation operation = compute.create(AddressInfo.of(addressId));
 // Wait for operation to complete
-operation.whenDone(new Operation.CompletionCallback() {
-  @Override
-  public void success(Operation operation) {
-    System.out.println("Address " + addressId + " was successfully created");
-  }
-
-  @Override
-  public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-    // inspect errors
-    throw new RuntimeException("Address creation failed");
-  }
-});
+operation = operation.waitFor();
+if (operation.errors() == null) {
+  System.out.println("Address " + addressId + " was successfully created");
+} else {
+  // inspect operation.errors()
+  throw new RuntimeException("Address creation failed");
+}
 ```
 
 #### Creating a persistent disk
@@ -157,18 +148,14 @@ DiskId diskId = DiskId.of("us-central1-a", "test-disk");
 ImageDiskConfiguration diskConfiguration = ImageDiskConfiguration.of(imageId);
 DiskInfo disk = DiskInfo.of(diskId, diskConfiguration);
 Operation operation = compute.create(disk);
-operation.whenDone(new Operation.CompletionCallback() {
-  @Override
-  public void success(Operation operation) {
-    System.out.println("Disk " + diskId + " was successfully created");
-  }
-
-  @Override
-  public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-    // inspect errors
-    throw new RuntimeException("Disk creation failed");
-  }
-});
+// Wait for operation to complete
+operation = operation.waitFor();
+if (operation.errors() == null) {
+  System.out.println("Disk " + diskId + " was successfully created");
+} else {
+  // inspect operation.errors()
+  throw new RuntimeException("Disk creation failed");
+}
 ```
 
 #### Creating a virtual machine instance
@@ -207,18 +194,14 @@ MachineTypeId machineTypeId = MachineTypeId.of("us-central1-a", "n1-standard-1")
 InstanceInfo instance =
     InstanceInfo.of(instanceId, machineTypeId, attachedDisk, networkInterface);
 Operation operation = compute.create(instance);
-operation.whenDone(new Operation.CompletionCallback() {
-  @Override
-  public void success(Operation operation) {
-    System.out.println("Instance " + instanceId + " was successfully created");
-  }
-
-  @Override
-  public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-    // inspect errors
-    throw new RuntimeException("Instance creation failed");
-  }
-});
+// Wait for operation to complete
+operation = operation.waitFor();
+if (operation.errors() == null) {
+  System.out.println("Instance " + instanceId + " was successfully created");
+} else {
+  // inspect operation.errors()
+  throw new RuntimeException("Instance creation failed");
+}
 ```
 
 #### Complete source code
diff --git a/gcloud-java-compute/src/main/java/com/google/cloud/compute/Operation.java b/gcloud-java-compute/src/main/java/com/google/cloud/compute/Operation.java
index 9ec6ccc54278..cf8afb04cfbb 100644
--- a/gcloud-java-compute/src/main/java/com/google/cloud/compute/Operation.java
+++ b/gcloud-java-compute/src/main/java/com/google/cloud/compute/Operation.java
@@ -36,6 +36,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Google Compute Engine operations. Operation identity can be obtained via {@link #operationId()}.
@@ -292,24 +293,6 @@ public int hashCode() {
     }
   }
 
-  /**
-   * A callback for operation completion.
-   */
-  public interface CompletionCallback {
-    /**
-     * The method called when the operation completes successfully.
-     */
-    void success(Operation operation);
-
-    /**
-     * The method called when the operation completes with errors. {@code errors} contains all
-     * errors encountered while processing this operation (see {@link Operation#errors()}).
-     * {@code warnings} contains all warnings encountered while processing this operation (see
-     * {@link Operation#warnings()}).
-     */
-    void error(List<OperationError> errors, List<OperationWarning> warnings);
-  }
-
   static final class Builder {
 
     private Compute compute;
@@ -677,40 +660,51 @@ public boolean isDone() {
   }
 
   /**
-   * Waits until this operation completes its execution, either failing or succeeding. If the
-   * operation does not exist, this method returns without executing any method of the provided
-   * callback. If the operation completed successfully the
-   * {@link CompletionCallback#success(Operation)} method is called. If the operation completed with
-   * errors the {@link CompletionCallback#error(List, List)} method is called.
+   * Blocks until this operation completes its execution, either failing or succeeding. The
+   * operation status is checked every 500 milliseconds. This method returns current operation's
+   * latest information. If the operation no longer exists, this method returns {@code null}.
    * <pre> {@code
-   * operation.whenDone(new CompletionCallback() {
-   *   void success(Operation operation) {
-   *     // completed successfully
-   *   }
+   * Operation completedOperation = operation.waitFor();
+   * if (completedOperation == null) {
+   *   // operation no longer exists
+   * } else if (completedOperation.errors() != null) {
+   *   // operation failed, handle error
+   * } else {
+   *   // operation completed successfully
+   * }}</pre>
    *
-   *   void error(List<OperationError> errors, List<OperationWarning> warnings) {
-   *     // handle error
-   *   }
-   * });}</pre>
+   * @throws ComputeException upon failure
+   * @throws InterruptedException if the current thread gets interrupted while waiting for the
+   *     operation to complete
+   */
+  public Operation waitFor() throws InterruptedException {
+    return waitFor(500, TimeUnit.MILLISECONDS);
+  }
+
+  /**
+   * Blocks until this operation completes its execution, either failing or succeeding. The
+   * {@code checkEvery} and {@code unit} parameters determine how often the operation status is
+   * checked. This method returns current operation's latest information. If the operation no longer
+   * exists, this method returns {@code null}.
+   * <pre> {@code
+   * Operation completedOperation = operation.waitFor(1, TimeUnit.SECONDS);
+   * if (completedOperation == null) {
+   *   // operation no longer exists
+   * } else if (completedOperation.errors() != null) {
+   *   // operation failed, handle error
+   * } else {
+   *   // operation completed successfully
+   * }}</pre>
    *
    * @throws ComputeException upon failure
    * @throws InterruptedException if the current thread gets interrupted while waiting for the
    *     operation to complete
    */
-  public void whenDone(CompletionCallback callback) throws InterruptedException {
+  public Operation waitFor(int checkEvery, TimeUnit unit) throws InterruptedException {
     while (!isDone()) {
-      Thread.sleep(500L);
-    }
-    Operation updatedOperation = reload();
-    if (updatedOperation == null) {
-      return;
-    }
-    List<OperationError> errors = updatedOperation.errors();
-    if (errors != null) {
-      callback.error(errors, updatedOperation.warnings());
-    } else {
-      callback.success(updatedOperation);
+      unit.sleep(checkEvery);
     }
+    return reload();
   }
 
   /**
diff --git a/gcloud-java-compute/src/main/java/com/google/cloud/compute/package-info.java b/gcloud-java-compute/src/main/java/com/google/cloud/compute/package-info.java
index 3b1c703fa9b0..da0a43ac43cf 100644
--- a/gcloud-java-compute/src/main/java/com/google/cloud/compute/package-info.java
+++ b/gcloud-java-compute/src/main/java/com/google/cloud/compute/package-info.java
@@ -28,17 +28,11 @@
  * if (disk != null) {
  *   final String snapshotName = "disk-name-snapshot";
  *   Operation operation = disk.createSnapshot(snapshotName);
- *   operation.whenDone(new Operation.CompletionCallback() {
- *     public void success(Operation operation) {
- *       // use snapshot
- *       Snapshot snapshot = compute.getSnapshot(snapshotName);
- *     }
- *
- *     public void error(List<OperationError> errors, List<OperationWarning> warnings) {
- *       // inspect errors
- *       throw new RuntimeException("Snaphsot creation failed");
- *     }
- *   });
+ *   operation = operation.waitFor();
+ *   if (operation.errors() == null) {
+ *     // use snapshot
+ *     Snapshot snapshot = compute.getSnapshot(snapshotName);
+ *   }
  * }}</pre>
  * <p>This second example shows how to create a virtual machine instance. Complete source code can
  * be found at
@@ -53,18 +47,12 @@
  * final InstanceId instanceId = InstanceId.of("us-central1-a", "instance-name");
  * MachineTypeId machineTypeId = MachineTypeId.of("us-central1-a", "n1-standard-1");
  * Operation operation =
- * compute.create(InstanceInfo.of(instanceId, machineTypeId, attachedDisk, networkInterface));
- * operation.whenDone(new Operation.CompletionCallback() {
- *   public void success(Operation operation) {
- *     // use instance
- *     Instance instance = compute.getInstance(instanceId);
- *   }
- *
- *   public void error(List<OperationError> errors, List<OperationWarning> warnings) {
- *     // inspect errors
- *     throw new RuntimeException("Instance creation failed");
- *   }
- * });}</pre>
+ *     compute.create(InstanceInfo.of(instanceId, machineTypeId, attachedDisk, networkInterface));
+ * operation = operation.waitFor();
+ * if (operation.errors() == null) {
+ *   // use instance
+ *   Instance instance = compute.getInstance(instanceId);
+ * }}</pre>
  *
  * @see <a href="https://cloud.google.com/compute/">Google Cloud Compute</a>
  */
diff --git a/gcloud-java-compute/src/test/java/com/google/cloud/compute/OperationTest.java b/gcloud-java-compute/src/test/java/com/google/cloud/compute/OperationTest.java
index b07411e1607e..63a0fc511d26 100644
--- a/gcloud-java-compute/src/test/java/com/google/cloud/compute/OperationTest.java
+++ b/gcloud-java-compute/src/test/java/com/google/cloud/compute/OperationTest.java
@@ -38,6 +38,7 @@
 import org.junit.Test;
 
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 public class OperationTest {
 
@@ -356,9 +357,8 @@ public void testIsDone_NotExists() throws Exception {
   }
 
   @Test
-  public void testWhenDone_Success() throws InterruptedException {
+  public void testWaitFor() throws InterruptedException {
     initializeExpectedOperation(4);
-    Operation.CompletionCallback callback = EasyMock.mock(Operation.CompletionCallback.class);
     Compute.OperationOption[] expectedOptions =
         {Compute.OperationOption.fields(Compute.OperationField.STATUS)};
     Operation successOperation =
@@ -366,44 +366,65 @@ public void testWhenDone_Success() throws InterruptedException {
     expect(compute.options()).andReturn(mockOptions);
     expect(compute.getOperation(GLOBAL_OPERATION_ID, expectedOptions)).andReturn(successOperation);
     expect(compute.getOperation(GLOBAL_OPERATION_ID)).andReturn(successOperation);
-    callback.success(successOperation);
-    EasyMock.expectLastCall();
-    replay(compute, callback);
+    replay(compute);
     initializeOperation();
-    operation.whenDone(callback);
-    verify(callback);
+    assertSame(successOperation, operation.waitFor());
   }
 
   @Test
-  public void testWhenDone_Error() throws InterruptedException {
+  public void testWaitFor_Null() throws InterruptedException {
     initializeExpectedOperation(3);
-    Operation.CompletionCallback callback = EasyMock.mock(Operation.CompletionCallback.class);
     Compute.OperationOption[] expectedOptions =
         {Compute.OperationOption.fields(Compute.OperationField.STATUS)};
     expect(compute.options()).andReturn(mockOptions);
-    expect(compute.getOperation(GLOBAL_OPERATION_ID, expectedOptions)).andReturn(globalOperation);
-    expect(compute.getOperation(GLOBAL_OPERATION_ID)).andReturn(globalOperation);
-    callback.error(ERRORS, WARNINGS);
+    expect(compute.getOperation(GLOBAL_OPERATION_ID, expectedOptions)).andReturn(null);
+    expect(compute.getOperation(GLOBAL_OPERATION_ID)).andReturn(null);
+    replay(compute);
+    initializeOperation();
+    assertNull(operation.waitFor());
+  }
+
+  @Test
+  public void testWaitForWithTimeUnit() throws InterruptedException {
+    initializeExpectedOperation(5);
+    Compute.OperationOption[] expectedOptions =
+        {Compute.OperationOption.fields(Compute.OperationField.STATUS)};
+    TimeUnit timeUnit = createStrictMock(TimeUnit.class);
+    timeUnit.sleep(42);
     EasyMock.expectLastCall();
-    replay(compute, callback);
+    Operation runningOperation = Operation.fromPb(serviceMockReturnsOptions,
+        globalOperation.toPb().setError(null).setStatus("RUNNING"));
+    Operation completedOperation =
+        Operation.fromPb(serviceMockReturnsOptions, globalOperation.toPb().setError(null));
+    expect(compute.options()).andReturn(mockOptions);
+    expect(compute.getOperation(GLOBAL_OPERATION_ID, expectedOptions)).andReturn(runningOperation);
+    expect(compute.getOperation(GLOBAL_OPERATION_ID, expectedOptions))
+        .andReturn(completedOperation);
+    expect(compute.getOperation(GLOBAL_OPERATION_ID)).andReturn(completedOperation);
+    replay(compute, timeUnit);
     initializeOperation();
-    operation.whenDone(callback);
-    verify(callback);
+    assertSame(completedOperation, operation.waitFor(42, timeUnit));
+    verify(timeUnit);
   }
 
   @Test
-  public void testWhenDone_Null() throws InterruptedException {
-    initializeExpectedOperation(3);
-    Operation.CompletionCallback callback = EasyMock.mock(Operation.CompletionCallback.class);
+  public void testWaitForWithTimeUnit_Null() throws InterruptedException {
+    initializeExpectedOperation(4);
     Compute.OperationOption[] expectedOptions =
         {Compute.OperationOption.fields(Compute.OperationField.STATUS)};
+    TimeUnit timeUnit = createStrictMock(TimeUnit.class);
+    timeUnit.sleep(42);
+    EasyMock.expectLastCall();
+    Operation runningOperation = Operation.fromPb(serviceMockReturnsOptions,
+        globalOperation.toPb().setError(null).setStatus("RUNNING"));
     expect(compute.options()).andReturn(mockOptions);
+    expect(compute.getOperation(GLOBAL_OPERATION_ID, expectedOptions)).andReturn(runningOperation);
     expect(compute.getOperation(GLOBAL_OPERATION_ID, expectedOptions)).andReturn(null);
     expect(compute.getOperation(GLOBAL_OPERATION_ID)).andReturn(null);
-    replay(compute, callback);
+    replay(compute, timeUnit);
     initializeOperation();
-    operation.whenDone(callback);
-    verify(callback);
+    assertNull(operation.waitFor(42, timeUnit));
+    verify(compute, timeUnit);
   }
 
   @Test
diff --git a/gcloud-java-compute/src/test/java/com/google/cloud/compute/it/ITComputeTest.java b/gcloud-java-compute/src/test/java/com/google/cloud/compute/it/ITComputeTest.java
index e67efd7e5ae2..ba9b58d775e1 100644
--- a/gcloud-java-compute/src/test/java/com/google/cloud/compute/it/ITComputeTest.java
+++ b/gcloud-java-compute/src/test/java/com/google/cloud/compute/it/ITComputeTest.java
@@ -56,9 +56,6 @@
 import com.google.cloud.compute.NetworkInfo;
 import com.google.cloud.compute.NetworkInterface;
 import com.google.cloud.compute.Operation;
-import com.google.cloud.compute.Operation.CompletionCallback;
-import com.google.cloud.compute.Operation.OperationError;
-import com.google.cloud.compute.Operation.OperationWarning;
 import com.google.cloud.compute.Region;
 import com.google.cloud.compute.RegionAddressId;
 import com.google.cloud.compute.RegionOperationId;
@@ -103,17 +100,6 @@ public class ITComputeTest {
   private static final ImageId IMAGE_ID = ImageId.of("debian-cloud", "debian-8-jessie-v20160219");
   private static final String IMAGE_PROJECT = "debian-cloud";
 
-  private static final CompletionCallback EMPTY_CALLBACK = new CompletionCallback() {
-    @Override
-    public void success(Operation operation) {
-      // do nothing
-    }
-
-    @Override
-    public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-      // do noting
-    }
-  };
   private static Compute compute;
 
   @Rule
@@ -700,7 +686,7 @@ public void testCreateGetAndDeleteRegionAddress() throws InterruptedException {
     AddressId addressId = RegionAddressId.of(REGION, name);
     AddressInfo addressInfo = AddressInfo.of(addressId);
     Operation operation = compute.create(addressInfo);
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     // test get
     Address remoteAddress = compute.getAddress(addressId);
     assertNotNull(remoteAddress);
@@ -721,7 +707,7 @@ public void testCreateGetAndDeleteRegionAddress() throws InterruptedException {
     assertNull(remoteAddress.creationTimestamp());
     assertNull(remoteAddress.generatedId());
     operation = remoteAddress.delete();
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     assertNull(compute.getAddress(addressId));
   }
 
@@ -733,8 +719,8 @@ public void testListRegionAddresses() throws InterruptedException {
     AddressId secondAddressId = RegionAddressId.of(REGION, addressNames[1]);
     Operation firstOperation = compute.create(AddressInfo.of(firstAddressId));
     Operation secondOperation = compute.create(AddressInfo.of(secondAddressId));
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     Set<String> addressSet = ImmutableSet.copyOf(addressNames);
     // test list
     Compute.AddressFilter filter =
@@ -785,8 +771,8 @@ public void testAggregatedListAddresses() throws InterruptedException {
     AddressId secondAddressId = GlobalAddressId.of(REGION, addressNames[1]);
     Operation firstOperation = compute.create(AddressInfo.of(firstAddressId));
     Operation secondOperation = compute.create(AddressInfo.of(secondAddressId));
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     Set<String> addressSet = ImmutableSet.copyOf(addressNames);
     Compute.AddressFilter filter =
         Compute.AddressFilter.equals(Compute.AddressField.NAME, prefix + "\\d");
@@ -814,7 +800,7 @@ public void testCreateGetAndDeleteGlobalAddress() throws InterruptedException {
     AddressId addressId = GlobalAddressId.of(name);
     AddressInfo addressInfo = AddressInfo.of(addressId);
     Operation operation = compute.create(addressInfo);
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     // test get
     Address remoteAddress = compute.getAddress(addressId);
     assertNotNull(remoteAddress);
@@ -833,7 +819,7 @@ public void testCreateGetAndDeleteGlobalAddress() throws InterruptedException {
     assertNull(remoteAddress.creationTimestamp());
     assertNull(remoteAddress.generatedId());
     operation = remoteAddress.delete();
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     assertNull(compute.getAddress(addressId));
   }
 
@@ -845,8 +831,8 @@ public void testListGlobalAddresses() throws InterruptedException {
     AddressId secondAddressId = GlobalAddressId.of(addressNames[1]);
     Operation firstOperation = compute.create(AddressInfo.of(firstAddressId));
     Operation secondOperation = compute.create(AddressInfo.of(secondAddressId));
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     Set<String> addressSet = ImmutableSet.copyOf(addressNames);
     // test list
     Compute.AddressFilter filter =
@@ -894,7 +880,7 @@ public void testCreateGetResizeAndDeleteStandardDisk() throws InterruptedExcepti
     DiskInfo diskInfo =
         DiskInfo.of(diskId, StandardDiskConfiguration.of(DiskTypeId.of(ZONE, "pd-ssd"), 100L));
     Operation operation = compute.create(diskInfo);
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     // test get
     Disk remoteDisk = compute.getDisk(diskId);
     assertNotNull(remoteDisk);
@@ -910,7 +896,7 @@ public void testCreateGetResizeAndDeleteStandardDisk() throws InterruptedExcepti
     assertNull(remoteDisk.lastAttachTimestamp());
     assertNull(remoteDisk.lastDetachTimestamp());
     operation = remoteDisk.resize(200L);
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     // test resize and get with selected fields
     remoteDisk = compute.getDisk(diskId, Compute.DiskOption.fields(Compute.DiskField.SIZE_GB));
     assertNotNull(remoteDisk);
@@ -926,7 +912,7 @@ public void testCreateGetResizeAndDeleteStandardDisk() throws InterruptedExcepti
     assertNull(remoteDisk.lastAttachTimestamp());
     assertNull(remoteDisk.lastDetachTimestamp());
     operation = remoteDisk.delete();
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     assertNull(compute.getDisk(diskId));
   }
 
@@ -936,7 +922,7 @@ public void testCreateGetAndDeleteImageDisk() throws InterruptedException {
     DiskId diskId = DiskId.of(ZONE, name);
     DiskInfo diskInfo = DiskInfo.of(diskId, ImageDiskConfiguration.of(IMAGE_ID));
     Operation operation = compute.create(diskInfo);
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     // test get
     Disk remoteDisk = compute.getDisk(diskId);
     assertNotNull(remoteDisk);
@@ -971,7 +957,7 @@ public void testCreateGetAndDeleteImageDisk() throws InterruptedException {
     assertNull(remoteDisk.lastAttachTimestamp());
     assertNull(remoteDisk.lastDetachTimestamp());
     operation = remoteDisk.delete();
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     assertNull(compute.getDisk(diskId));
   }
 
@@ -985,10 +971,10 @@ public void testCreateGetAndDeleteSnapshotAndSnapshotDisk() throws InterruptedEx
     DiskInfo diskInfo =
         DiskInfo.of(diskId, StandardDiskConfiguration.of(DiskTypeId.of(ZONE, "pd-ssd"), 100L));
     Operation operation = compute.create(diskInfo);
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     Disk remoteDisk = compute.getDisk(diskId);
     operation = remoteDisk.createSnapshot(snapshotName);
-    operation.whenDone(EMPTY_CALLBACK);
+    operation.waitFor();
     // test get snapshot with selected fields
     Snapshot snapshot = compute.getSnapshot(snapshotName,
         Compute.SnapshotOption.fields(Compute.SnapshotField.CREATION_TIMESTAMP));
@@ -1018,7 +1004,7 @@ public void testCreateGetAndDeleteSnapshotAndSnapshotDisk() throws InterruptedEx
     diskInfo =
         DiskInfo.of(snapshotDiskId, SnapshotDiskConfiguration.of(SnapshotId.of(snapshotName)));
     operation = compute.create(diskInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     // test get disk
     remoteDisk = compute.getDisk(snapshotDiskId);
     assertNotNull(remoteDisk);
@@ -1054,10 +1040,10 @@ public void testCreateGetAndDeleteSnapshotAndSnapshotDisk() throws InterruptedEx
     assertNull(remoteDisk.lastAttachTimestamp());
     assertNull(remoteDisk.lastDetachTimestamp());
     operation = remoteDisk.delete();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getDisk(snapshotDiskId));
     operation = snapshot.delete();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getSnapshot(snapshotName));
   }
 
@@ -1071,8 +1057,8 @@ public void testListDisksAndSnapshots() throws InterruptedException {
         StandardDiskConfiguration.of(DiskTypeId.of(ZONE, "pd-ssd"), 100L);
     Operation firstOperation = compute.create(DiskInfo.of(firstDiskId, configuration));
     Operation secondOperation = compute.create(DiskInfo.of(secondDiskId, configuration));
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     Set<String> diskSet = ImmutableSet.copyOf(diskNames);
     // test list disks
     Compute.DiskFilter diskFilter =
@@ -1124,8 +1110,8 @@ public void testListDisksAndSnapshots() throws InterruptedException {
     SnapshotId secondSnapshotId = SnapshotId.of(diskNames[1]);
     firstOperation = compute.create(SnapshotInfo.of(firstSnapshotId, firstDiskId));
     secondOperation = compute.create(SnapshotInfo.of(secondSnapshotId, secondDiskId));
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     // test list snapshots
     Compute.SnapshotFilter snapshotFilter =
         Compute.SnapshotFilter.equals(Compute.SnapshotField.NAME, prefix + "\\d");
@@ -1183,8 +1169,8 @@ public void testAggregatedListDisks() throws InterruptedException {
         StandardDiskConfiguration.of(DiskTypeId.of(ZONE, "pd-ssd"), 100L);
     Operation firstOperation = compute.create(DiskInfo.of(firstDiskId, configuration));
     Operation secondOperation = compute.create(DiskInfo.of(secondDiskId, configuration));
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     Set<String> zoneSet = ImmutableSet.copyOf(diskZones);
     Set<String> diskSet = ImmutableSet.copyOf(diskNames);
     Compute.DiskFilter diskFilter =
@@ -1220,11 +1206,11 @@ public void testCreateGetAndDeprecateImage() throws InterruptedException {
     DiskInfo diskInfo =
         DiskInfo.of(diskId, StandardDiskConfiguration.of(DiskTypeId.of(ZONE, "pd-ssd"), 100L));
     Operation operation = compute.create(diskInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     Disk remoteDisk = compute.getDisk(diskId);
     ImageInfo imageInfo = ImageInfo.of(imageId, DiskImageConfiguration.of(diskId));
     operation = compute.create(imageInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     // test get image with selected fields
     Image image = compute.getImage(imageId,
         Compute.ImageOption.fields(Compute.ImageField.CREATION_TIMESTAMP));
@@ -1260,12 +1246,12 @@ public void testCreateGetAndDeprecateImage() throws InterruptedException {
             .deprecated(System.currentTimeMillis())
             .build();
     operation = image.deprecate(deprecationStatus);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     image = compute.getImage(imageId);
     assertEquals(deprecationStatus, image.deprecationStatus());
     remoteDisk.delete();
     operation = image.delete();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getImage(imageId));
   }
 
@@ -1336,7 +1322,7 @@ public void testCreateAndGetNetwork() throws InterruptedException {
     NetworkInfo networkInfo =
         NetworkInfo.of(networkId, StandardNetworkConfiguration.of("192.168.0.0/16"));
     Operation operation = compute.create(networkInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     // test get network with selected fields
     Network network = compute.getNetwork(networkId.network(),
         Compute.NetworkOption.fields(Compute.NetworkField.CREATION_TIMESTAMP));
@@ -1356,7 +1342,7 @@ public void testCreateAndGetNetwork() throws InterruptedException {
     remoteConfiguration = network.configuration();
     assertEquals("192.168.0.0/16", remoteConfiguration.ipRange());
     operation = network.delete();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getNetwork(name));
   }
 
@@ -1367,7 +1353,7 @@ public void testListNetworks() throws InterruptedException {
     NetworkInfo networkInfo =
         NetworkInfo.of(networkId, StandardNetworkConfiguration.of("192.168.0.0/16"));
     Operation operation = compute.create(networkInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     // test list
     Compute.NetworkFilter filter = Compute.NetworkFilter.equals(Compute.NetworkField.NAME, name);
     Page<Network> networkPage = compute.listNetworks(Compute.NetworkListOption.filter(filter));
@@ -1402,7 +1388,7 @@ public void testListNetworks() throws InterruptedException {
     }
     assertEquals(1, count);
     operation = compute.deleteNetwork(networkId);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getNetwork(name));
   }
 
@@ -1412,7 +1398,7 @@ public void testCreateNetworkAndSubnetwork() throws InterruptedException {
     NetworkId networkId = NetworkId.of(networkName);
     NetworkInfo networkInfo = NetworkInfo.of(networkId, SubnetNetworkConfiguration.of(false));
     Operation operation = compute.create(networkInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     // test get network
     Network network = compute.getNetwork(networkId.network());
     assertEquals(networkId.network(), network.networkId().network());
@@ -1425,7 +1411,7 @@ public void testCreateNetworkAndSubnetwork() throws InterruptedException {
     SubnetworkId subnetworkId = SubnetworkId.of(REGION, subnetworkName);
     SubnetworkInfo subnetworkInfo = SubnetworkInfo.of(subnetworkId, networkId, "192.168.0.0/16");
     operation = compute.create(subnetworkInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     // test get subnetwork with selected fields
     Subnetwork subnetwork = compute.getSubnetwork(subnetworkId,
         Compute.SubnetworkOption.fields(Compute.SubnetworkField.CREATION_TIMESTAMP));
@@ -1480,9 +1466,9 @@ public void testCreateNetworkAndSubnetwork() throws InterruptedException {
     }
     assertEquals(1, count);
     operation = subnetwork.delete();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     operation = compute.deleteNetwork(networkId);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getSubnetwork(subnetworkId));
     assertNull(compute.getNetwork(networkName));
   }
@@ -1493,7 +1479,7 @@ public void testAggregatedListSubnetworks() throws InterruptedException {
     NetworkId networkId = NetworkId.of(networkName);
     NetworkInfo networkInfo = NetworkInfo.of(networkId, SubnetNetworkConfiguration.of(false));
     Operation operation = compute.create(networkInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     String prefix = BASE_RESOURCE_NAME + "list-subnetwork";
     String[] regionNames = {"us-central1", "us-east1"};
     String[] subnetworkNames = {prefix + "1", prefix + "2"};
@@ -1506,8 +1492,8 @@ public void testAggregatedListSubnetworks() throws InterruptedException {
         SubnetworkInfo.of(secondSubnetworkId, networkId, ipRanges[1]);
     Operation firstOperation = compute.create(firstSubnetworkInfo);
     Operation secondOperation = compute.create(secondSubnetworkInfo);
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     Set<String> regionSet = ImmutableSet.copyOf(regionNames);
     Set<String> subnetworkSet = ImmutableSet.copyOf(subnetworkNames);
     Set<String> rangeSet = ImmutableSet.copyOf(ipRanges);
@@ -1531,10 +1517,10 @@ public void testAggregatedListSubnetworks() throws InterruptedException {
     assertEquals(2, count);
     firstOperation = compute.deleteSubnetwork(firstSubnetworkId);
     secondOperation = compute.deleteSubnetwork(secondSubnetworkId);
-    firstOperation.whenDone(EMPTY_CALLBACK);
-    secondOperation.whenDone(EMPTY_CALLBACK);
+    firstOperation.waitFor();
+    secondOperation.waitFor();
     operation = compute.deleteNetwork(networkId);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getNetwork(networkName));
   }
 
@@ -1546,7 +1532,7 @@ public void testCreateGetAndDeleteInstance() throws InterruptedException {
     AddressId addressId = RegionAddressId.of(REGION, addressName);
     AddressInfo addressInfo = AddressInfo.of(addressId);
     Operation operation = compute.create(addressInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     Address address = compute.getAddress(addressId);
     // Create an instance
     InstanceId instanceId = InstanceId.of(ZONE, instanceName);
@@ -1564,7 +1550,7 @@ public void testCreateGetAndDeleteInstance() throws InterruptedException {
             .networkInterfaces(networkInterface)
             .build();
     operation = compute.create(instanceInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     // test get
     Instance remoteInstance = compute.getInstance(instanceId);
     assertEquals(instanceName, remoteInstance.instanceId().instance());
@@ -1616,7 +1602,7 @@ public void testCreateGetAndDeleteInstance() throws InterruptedException {
     String newSerialPortOutput = remoteInstance.getSerialPortOutput(1);
     assertTrue(newSerialPortOutput.contains(serialPortOutput));
     operation = remoteInstance.delete();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     assertNull(compute.getInstance(instanceId));
     address.delete();
   }
@@ -1635,22 +1621,22 @@ public void testStartStopAndResetInstance() throws InterruptedException {
             .networkInterfaces(networkInterface)
             .build();
     Operation operation = compute.create(instanceInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     Instance remoteInstance = compute.getInstance(instanceId,
         Compute.InstanceOption.fields(Compute.InstanceField.STATUS));
     assertEquals(InstanceInfo.Status.RUNNING, remoteInstance.status());
     operation = remoteInstance.stop();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     remoteInstance = compute.getInstance(instanceId,
         Compute.InstanceOption.fields(Compute.InstanceField.STATUS));
     assertEquals(InstanceInfo.Status.TERMINATED, remoteInstance.status());
     operation = remoteInstance.start();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     remoteInstance = compute.getInstance(instanceId,
         Compute.InstanceOption.fields(Compute.InstanceField.STATUS));
     assertEquals(InstanceInfo.Status.RUNNING, remoteInstance.status());
     operation = remoteInstance.reset();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     remoteInstance = compute.getInstance(instanceId,
         Compute.InstanceOption.fields(Compute.InstanceField.STATUS));
     assertEquals(InstanceInfo.Status.RUNNING, remoteInstance.status());
@@ -1671,32 +1657,32 @@ public void testSetInstanceProperties() throws InterruptedException {
             .networkInterfaces(networkInterface)
             .build();
     Operation operation = compute.create(instanceInfo);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     Instance remoteInstance = compute.getInstance(instanceId);
     // test set tags
     List<String> tags = ImmutableList.of("tag1", "tag2");
     operation = remoteInstance.setTags(tags);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     assertEquals(tags, remoteInstance.tags().values());
     // test set metadata
     Map<String, String> metadata = ImmutableMap.of("key", "value");
     operation = remoteInstance.setMetadata(metadata);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     assertEquals(metadata, remoteInstance.metadata().values());
     // test set machine type
     operation = remoteInstance.stop();
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     operation = remoteInstance.setMachineType(MachineTypeId.of(ZONE, "n1-standard-1"));
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     assertEquals("n1-standard-1", remoteInstance.machineType().type());
     assertEquals(ZONE, remoteInstance.machineType().zone());
     // test set scheduling options
     SchedulingOptions options = SchedulingOptions.standard(false, SchedulingOptions.Maintenance.TERMINATE);
     operation = remoteInstance.setSchedulingOptions(options);
-operation.whenDone(EMPTY_CALLBACK);
+operation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     assertEquals(options, remoteInstance.schedulingOptions());
     remoteInstance.delete();
@@ -1720,13 +1706,13 @@ public void testAttachAndDetachDisk() throws InterruptedException {
     DiskId diskId = DiskId.of(ZONE, diskName);
     Operation diskOperation = compute.create(DiskInfo.of(diskId,
             StandardDiskConfiguration.of(DiskTypeId.of(ZONE, "pd-ssd"))));
-    instanceOperation.whenDone(EMPTY_CALLBACK);
-    diskOperation.whenDone(EMPTY_CALLBACK);
+    instanceOperation.waitFor();
+    diskOperation.waitFor();
     Instance remoteInstance = compute.getInstance(instanceId);
     // test attach disk
     instanceOperation = remoteInstance.attachDisk("dev1",
         AttachedDisk.PersistentDiskConfiguration.builder(diskId).build());
-    instanceOperation.whenDone(EMPTY_CALLBACK);
+    instanceOperation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     Set<String> deviceSet = ImmutableSet.of("dev0", "dev1");
     assertEquals(2, remoteInstance.attachedDisks().size());
@@ -1735,7 +1721,7 @@ public void testAttachAndDetachDisk() throws InterruptedException {
     }
     // test set disk auto-delete
     instanceOperation = remoteInstance.setDiskAutoDelete("dev1", true);
-    instanceOperation.whenDone(EMPTY_CALLBACK);
+    instanceOperation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     assertEquals(2, remoteInstance.attachedDisks().size());
     for (AttachedDisk remoteAttachedDisk : remoteInstance.attachedDisks()) {
@@ -1744,7 +1730,7 @@ public void testAttachAndDetachDisk() throws InterruptedException {
     }
     // test detach disk
     instanceOperation = remoteInstance.detachDisk("dev1");
-    instanceOperation.whenDone(EMPTY_CALLBACK);
+    instanceOperation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     assertEquals(1, remoteInstance.attachedDisks().size());
     assertEquals("dev0", remoteInstance.attachedDisks().get(0).deviceName());
@@ -1770,8 +1756,8 @@ public void testAddAndRemoveAccessConfig() throws InterruptedException {
     AddressId addressId = RegionAddressId.of(REGION, addressName);
     AddressInfo addressInfo = AddressInfo.of(addressId);
     Operation addressOperation = compute.create(addressInfo);
-    addressOperation.whenDone(EMPTY_CALLBACK);
-    instanceOperation.whenDone(EMPTY_CALLBACK);
+    addressOperation.waitFor();
+    instanceOperation.waitFor();
     Address remoteAddress = compute.getAddress(addressId);
     Instance remoteInstance = compute.getInstance(instanceId);
     String networkInterfaceName = remoteInstance.networkInterfaces().get(0).name();
@@ -1781,7 +1767,7 @@ public void testAddAndRemoveAccessConfig() throws InterruptedException {
         .name("NAT")
         .build();
     instanceOperation = remoteInstance.addAccessConfig(networkInterfaceName, accessConfig);
-    instanceOperation.whenDone(EMPTY_CALLBACK);
+    instanceOperation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     List<NetworkInterface.AccessConfig> accessConfigurations =
         remoteInstance.networkInterfaces().get(0).accessConfigurations();
@@ -1789,7 +1775,7 @@ public void testAddAndRemoveAccessConfig() throws InterruptedException {
     assertEquals("NAT", accessConfigurations.get(0).name());
     // test delete access config
     instanceOperation = remoteInstance.deleteAccessConfig(networkInterfaceName, "NAT");
-    instanceOperation.whenDone(EMPTY_CALLBACK);
+    instanceOperation.waitFor();
     remoteInstance = compute.getInstance(instanceId);
     assertTrue(remoteInstance.networkInterfaces().get(0).accessConfigurations().isEmpty());
     remoteInstance.delete();
diff --git a/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/BigQueryExample.java b/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/BigQueryExample.java
index 41cacef7ed00..156e475a5ac9 100644
--- a/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/BigQueryExample.java
+++ b/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/BigQueryExample.java
@@ -523,19 +523,18 @@ private abstract static class JobRunAction extends BigQueryAction<JobInfo> {
     @Override
     void run(BigQuery bigquery, JobInfo job) throws Exception {
       System.out.println("Creating job");
-      final Job startedJob = bigquery.create(job);
-      startedJob.whenDone(new Job.CompletionCallback() {
-        @Override
-        public void success(Job updatedJob) {
-          System.out.println("Job " + updatedJob.jobId().job() + " succeeded");
-        }
-
-        @Override
-        public void error(BigQueryError error, List<BigQueryError> executionErrors) {
-          System.out.println("Job " + startedJob.jobId().job() + " failed");
-          System.out.println("Error: " + startedJob.status().error());
-        }
-      });
+      Job startedJob = bigquery.create(job);
+      while (!startedJob.isDone()) {
+        System.out.println("Waiting for job " + startedJob.jobId().job() + " to complete");
+        Thread.sleep(1000L);
+      }
+      startedJob = startedJob.reload();
+      if (startedJob.status().error() == null) {
+        System.out.println("Job " + startedJob.jobId().job() + " succeeded");
+      } else {
+        System.out.println("Job " + startedJob.jobId().job() + " failed");
+        System.out.println("Error: " + startedJob.status().error());
+      }
     }
   }
 
diff --git a/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/snippets/CreateTableAndLoadData.java b/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/snippets/CreateTableAndLoadData.java
index e74bbc3723cc..8dd76b0265f8 100644
--- a/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/snippets/CreateTableAndLoadData.java
+++ b/gcloud-java-examples/src/main/java/com/google/cloud/examples/bigquery/snippets/CreateTableAndLoadData.java
@@ -23,7 +23,6 @@
 package com.google.cloud.examples.bigquery.snippets;
 
 import com.google.cloud.bigquery.BigQuery;
-import com.google.cloud.bigquery.BigQueryError;
 import com.google.cloud.bigquery.BigQueryOptions;
 import com.google.cloud.bigquery.Field;
 import com.google.cloud.bigquery.FormatOptions;
@@ -34,8 +33,6 @@
 import com.google.cloud.bigquery.TableId;
 import com.google.cloud.bigquery.TableInfo;
 
-import java.util.List;
-
 /**
  * A snippet for Google Cloud BigQuery showing how to get a BigQuery table or create it if it does
  * not exist. The snippet also starts a BigQuery job to load data into the table from a Cloud
@@ -55,16 +52,11 @@ public static void main(String... args) throws InterruptedException {
     }
     System.out.println("Loading data into table " + tableId);
     Job loadJob = table.load(FormatOptions.csv(), "gs://bucket/path");
-    loadJob.whenDone(new Job.CompletionCallback() {
-      @Override
-      public void success(Job job) {
-        System.out.println("Job succeeded");
-      }
-
-      @Override
-      public void error(BigQueryError error, List<BigQueryError> executionErrors) {
-        System.out.println("Job completed with errors");
-      }
-    });
+    loadJob = loadJob.waitFor();
+    if (loadJob.status().error() != null) {
+      System.out.println("Job completed with errors");
+    } else {
+      System.out.println("Job succeeded");
+    }
   }
 }
diff --git a/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateAddressDiskAndInstance.java b/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateAddressDiskAndInstance.java
index 4948f68b6db8..04d2116e0a75 100644
--- a/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateAddressDiskAndInstance.java
+++ b/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateAddressDiskAndInstance.java
@@ -33,12 +33,8 @@
 import com.google.cloud.compute.NetworkInterface;
 import com.google.cloud.compute.NetworkInterface.AccessConfig;
 import com.google.cloud.compute.Operation;
-import com.google.cloud.compute.Operation.OperationError;
-import com.google.cloud.compute.Operation.OperationWarning;
 import com.google.cloud.compute.RegionAddressId;
 
-import java.util.List;
-
 /**
  * A snippet for Google Cloud Compute Engine showing how to create a disk and an address. The
  * snippet also shows how to create a virtual machine instance using the created disk and address.
@@ -54,18 +50,13 @@ public static void main(String... args) throws InterruptedException {
     final RegionAddressId addressId = RegionAddressId.of("us-central1", "test-address");
     Operation operation = compute.create(AddressInfo.of(addressId));
     // Wait for operation to complete
-    operation.whenDone(new Operation.CompletionCallback() {
-      @Override
-      public void success(Operation operation) {
-        System.out.println("Address " + addressId + " was successfully created");
-      }
-
-      @Override
-      public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-        // inspect errors
-        throw new RuntimeException("Address creation failed");
-      }
-    });
+    operation = operation.waitFor();
+    if (operation.errors() == null) {
+      System.out.println("Address " + addressId + " was successfully created");
+    } else {
+      // inspect operation.errors()
+      throw new RuntimeException("Address creation failed");
+    }
 
     // Create a persistent disk
     ImageId imageId = ImageId.of("debian-cloud", "debian-8-jessie-v20160329");
@@ -74,18 +65,13 @@ public void error(List<OperationError> errors, List<OperationWarning> warnings)
     DiskInfo disk = DiskInfo.of(diskId, diskConfiguration);
     operation = compute.create(disk);
     // Wait for operation to complete
-    operation.whenDone(new Operation.CompletionCallback() {
-      @Override
-      public void success(Operation operation) {
-        System.out.println("Disk " + diskId + " was successfully created");
-      }
-
-      @Override
-      public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-        // inspect errors
-        throw new RuntimeException("Disk creation failed");
-      }
-    });
+    operation = operation.waitFor();
+    if (operation.errors() == null) {
+      System.out.println("Disk " + diskId + " was successfully created");
+    } else {
+      // inspect operation.errors()
+      throw new RuntimeException("Disk creation failed");
+    }
 
     // Create a virtual machine instance
     Address externalIp = compute.getAddress(addressId);
@@ -102,17 +88,12 @@ public void error(List<OperationError> errors, List<OperationWarning> warnings)
         InstanceInfo.of(instanceId, machineTypeId, attachedDisk, networkInterface);
     operation = compute.create(instance);
     // Wait for operation to complete
-    operation.whenDone(new Operation.CompletionCallback() {
-      @Override
-      public void success(Operation operation) {
-        System.out.println("Instance " + instanceId + " was successfully created");
-      }
-
-      @Override
-      public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-        // inspect errors
-        throw new RuntimeException("Instance creation failed");
-      }
-    });
+    operation = operation.waitFor();
+    if (operation.errors() == null) {
+      System.out.println("Instance " + instanceId + " was successfully created");
+    } else {
+      // inspect operation.errors()
+      throw new RuntimeException("Instance creation failed");
+    }
   }
 }
diff --git a/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateInstance.java b/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateInstance.java
index 0e70aa2ea83f..c144edcd3042 100644
--- a/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateInstance.java
+++ b/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateInstance.java
@@ -27,10 +27,6 @@
 import com.google.cloud.compute.NetworkId;
 import com.google.cloud.compute.NetworkInterface;
 import com.google.cloud.compute.Operation;
-import com.google.cloud.compute.Operation.OperationError;
-import com.google.cloud.compute.Operation.OperationWarning;
-
-import java.util.List;
 
 /**
  * A snippet for Google Cloud Compute Engine showing how to create a virtual machine instance.
@@ -47,18 +43,10 @@ public static void main(String... args) throws InterruptedException {
     MachineTypeId machineTypeId = MachineTypeId.of("us-central1-a", "n1-standard-1");
     Operation operation =
         compute.create(InstanceInfo.of(instanceId, machineTypeId, attachedDisk, networkInterface));
-    operation.whenDone(new Operation.CompletionCallback() {
-      @Override
-      public void success(Operation operation) {
-        // use instance
-        Instance instance = compute.getInstance(instanceId);
-      }
-
-      @Override
-      public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-        // inspect errors
-        throw new RuntimeException("Instance creation failed");
-      }
-    });
+    operation = operation.waitFor();
+    if (operation.errors() == null) {
+      // use instance
+      Instance instance = compute.getInstance(instanceId);
+    }
   }
 }
diff --git a/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateSnapshot.java b/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateSnapshot.java
index 1c364bf0c353..5f74f1a37fb7 100644
--- a/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateSnapshot.java
+++ b/gcloud-java-examples/src/main/java/com/google/cloud/examples/compute/snippets/CreateSnapshot.java
@@ -21,12 +21,8 @@
 import com.google.cloud.compute.Disk;
 import com.google.cloud.compute.DiskId;
 import com.google.cloud.compute.Operation;
-import com.google.cloud.compute.Operation.OperationError;
-import com.google.cloud.compute.Operation.OperationWarning;
 import com.google.cloud.compute.Snapshot;
 
-import java.util.List;
-
 /**
  * A snippet for Google Cloud Compute Engine showing how to create a snapshot of a disk if the disk
  * exists.
@@ -40,19 +36,11 @@ public static void main(String... args) throws InterruptedException {
     if (disk != null) {
       final String snapshotName = "disk-name-snapshot";
       Operation operation = disk.createSnapshot(snapshotName);
-      operation.whenDone(new Operation.CompletionCallback() {
-        @Override
-        public void success(Operation operation) {
-          // use snapshot
-          Snapshot snapshot = compute.getSnapshot(snapshotName);
-        }
-
-        @Override
-        public void error(List<OperationError> errors, List<OperationWarning> warnings) {
-          // inspect errors
-          throw new RuntimeException("Snaphsot creation failed");
-        }
-      });
+      operation = operation.waitFor();
+      if (operation.errors() == null) {
+        // use snapshot
+        Snapshot snapshot = compute.getSnapshot(snapshotName);
+      }
     }
   }
 }