Busbud Coding Challenge

Design decisions

• Use of a Mongo DB sandbox to store the data
• Calculate the score based on Pythagoras rule (Classification)
• Query all the cities based on prefix
• Heroku app can be found at https://floating-wave-87999.herokuapp.com/suggestions?q=montreal
• Additional fields can be added such as https://floating-wave-87999.herokuapp.com/suggestions?q=london&latitude=45.508&longitude=-73.5871
• Results are ordered in decreasing order of score and chronological order of name for similar scores

Server upgrades

• Server went up to 10x faster than originally on (30 rps to 300rps)
• Clustering feature of node js is used
• Common cache among clusters is used

Requirements

Design an API endpoint that provides auto-complete suggestions for large cities. The suggestions should be restricted to cities in the USA and Canada with a population above 5000 people.

• the endpoint is exposed at /suggestions
• the partial (or complete) search term is passed as a querystring parameter q
• the caller's location can optionally be supplied via querystring parameters latitude and longitude to help improve relative scores
• the endpoint returns a JSON response with an array of scored suggested matches
  • the suggestions are sorted by descending score
  • each suggestion has a score between 0 and 1 (inclusive) indicating confidence in the suggestion (1 is most confident)
  • each suggestion has a name which can be used to disambiguate between similarly named locations
  • each suggestion has a latitude and longitude
• all functional tests should pass (additional tests may be implemented as necessary).
• the final application should be deployed to Heroku.
• feel free to add more features if you like!

Sample responses

These responses are meant to provide guidance. The exact values can vary based on the data source and scoring algorithm

Near match

GET /suggestions?q=Londo&latitude=43.70011&longitude=-79.4163

{
  "suggestions": [
    {
      "name": "London, ON, Canada",
      "latitude": "42.98339",
      "longitude": "-81.23304",
      "score": 0.9
    },
    {
      "name": "London, OH, USA",
      "latitude": "39.88645",
      "longitude": "-83.44825",
      "score": 0.5
    },
    {
      "name": "London, KY, USA",
      "latitude": "37.12898",
      "longitude": "-84.08326",
      "score": 0.5
    },
    {
      "name": "Londontowne, MD, USA",
      "latitude": "38.93345",
      "longitude": "-76.54941",
      "score": 0.3
    }
  ]
}

No match

GET /suggestions?q=SomeRandomCityInTheMiddleOfNowhere

{
  "suggestions": []
}

Non-functional

• All code should be written in Javascript
• Mitigations to handle high levels of traffic should be implemented
• Work should be submitted as a pull-request to this repo
• Documentation and maintainability is a plus

References

• Geonames provides city lists Canada and the USA http://download.geonames.org/export/dump/readme.txt
• http://www.nodejs.org/
• http://ejohn.org/blog/node-js-stream-playground/

Getting Started

Begin by forking this repo and cloning your fork. GitHub has apps for Mac and Windows that make this easier.

Setting up a Nodejs environment

Get started by installing nodejs.

For OS X users, use Homebrew and brew install nvm

Once that's done, from the project directory, run

nvm use

Setting up the project

In the project directory run

npm install

Running the tests

The test suite can be run with

npm test

Starting the application

To start a local server run

PORT=3456 npm start

which should produce output similar to

Server running at http://127.0.0.1:2345/suggestions