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!

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": []
}

• All code should be written in Ruby
• 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

• Geonames provides city lists Canada and the USA http://download.geonames.org/export/dump/readme.txt
• http://www.sinatrarb.com/

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

Get started by installing rbenv and ruby-build.

For OS X users, this will require the Xcode Command Line tools and a few Homebrew packages. Details here.

Once that's done run

rbenv install 2.0.0-p247

followed by

rbenv shell 2.0.0-p247

In the project directory run

gem install bundler

followed by

bundle install

(You may need to run rbenv rehash if the bundle command is unavailable).

The test suite can be run with

bundle exec rspec

To start a local server run

bundle exec thin start

which should produce output similar to

Using rack adapter
Thin web server (v1.6.1 codename Death Proof)
Maximum connections set to 1024
Listening on 0.0.0.0:3000, CTRL+C to stop