Bids

This is a small microservice, resposible for handling bid amounts for our Pay Per Click bids platform. Other applications use this service to know what is the bid amount for a combination of country, category, and channel.

Definitions

Bid: The amount a vendor bids to pay for a click in a given country, category, and channel.
Country: ISO 3166-1 alpha-2 country code. This microservice does not care about country names or any information other than the code.
Category: A string code for a given category in our websites, for example: crm, finance, sports, hr...
Channel: The string code for one of our websites. Capterra: ca, GetApp: ga, Software Advice: sa

Business logic

Bids are organized into defaults and overrides. Bidders are allowed to enter in bids that target a specific country, category, and channel, or, they can provide defaults at either the country, or, country/category level.

Given a sample bids table containing the following data:

country	category	channel	amount
us	finance	ca	4.0
uk	sports	*	3.0
us	*	*	2.0
*	*	*	1.0

this means that:

The bid amount for the us,finance,ca combination is $4.00
The bid amount for uk,sports in any channel would be $3.00
Any combination in the us other than us,finance,ca would have $2.00 bid amount
And any other combination would have $1.00 as bid amount

Code challenge

The challenge is to create a /bids API endpoint that would allow other applications to request the bid amounts for different country, category and channel combinations. The endpoint should accept comma-separated lists of countries, categories and channels as parameters, and return a JSON object containing the array with all the combinations and the amount for each.

Sample request:

GET /bids?countries=us,uk&categories=finance,sports&channels=ca,ga

And the expected response is:

{
  "bids": [
    { 'country': 'us', 'category': 'finance', 'channel': 'ca', 'amount': 4.0 },
    { 'country': 'us', 'category': 'finance', 'channel': 'ga', 'amount': 2.0 },
    { 'country': 'us', 'category': 'sports', 'channel': 'ca', 'amount': 2.0 },
    { 'country': 'us', 'category': 'sports', 'channel': 'ga', 'amount': 2.0 },
    { 'country': 'uk', 'category': 'finance', 'channel': 'ca', 'amount': 1.0 },
    { 'country': 'uk', 'category': 'finance', 'channel': 'ga', 'amount': 1.0 },
    { 'country': 'uk', 'category': 'sports', 'channel': 'ca', 'amount': 3.0 },
    { 'country': 'uk', 'category': 'sports', 'channel': 'ga', 'amount': 3.0 }
  ]
}

For data storage, the code already provides a model mapped to a relational database table, but feel free to explore other solutions.

Docker

The app can be run either locally or using Docker. If Ruby 3.1 is not installed in the local system, Docker can be used for convenience. The repository contains a docker-compose.yml file. Examples:

How to run the test suite

$  docker-compose run app bundle exec rspec

How to run Rails console

$  docker-compose run app bundle exec rails console

Submitting Code

Please create a pull request in this repository with:

A well written and performant solution, implemented in Ruby.
The tests must pass
Add as many tests as you think you need
Good PR description containing your solution explanation as well as any pertinent information
You can use whatever libraries you would like, as long as they can all be installed using bundle install. Please explain and justify your library choices in the PR description

Grading criteria

Correctness: solutions must produce correct result sets given any valid input
Readability & Organization: code should be well organized and readable with well thought out architecture and naming choices
Well-organized git history is a plus

rajneeshsharma9/zip-bids-endpoint-challenge