Node Backend Technical Challenge

You've been tasked with building a new "cards" service for the front-end of the Moonpig website. This exercise requires building a simple REST-like API with two endpoints - one for returning a list of cards and another that returns a single instance of a card.

We have provided three JSON files that serve as source data - you can find them at the following URLs:

• https://moonpig.github.io/tech-test-node-backend/cards.json
• https://moonpig.github.io/tech-test-node-backend/sizes.json
• https://moonpig.github.io/tech-test-node-backend/templates.json

Please treat these as a remote data source, rather than manually downloading and integrating into your application locally.

Notes

We have provided a notes file NOTES.md for any notes that you wish to add that could help your application such as explaining why you've made certain decisions or any incomplete aspects of your solution.

Please timebox your efforts to 4 hours. Add any comments or suggestions for further improvements to the NOTES.md file. While we are not expecting a fully feature-complete solution, we are looking for the same mindset you would apply to production code — such as trade-offs, maintainability, and API design and engineering best practices. We are particularly interested in evaluating your technical capability and approach to problem solving.

For your convenience we've made this a template repository so you can easily create a private copy.

Please commit frequently so we can see your approach and ensure you submit the .git folder alongside your code. When it comes to submission please follow the instructions provided in the email you were sent.

Endpoints

/cards

This endpoint returns a list of cards.

• imageUrl should be the image found on the template that corresponds to the first page for the card.
• url should have the format /cards/[id]

Expected JSON response from GET /cards:

[
  {
    "title": "card 1 title",
    "imageUrl": "/front-cover-portrait-1.jpg",
    "url": "/cards/card001"
  },
  {
    "title": "card 2 title",
    "imageUrl": "/front-cover-portrait-2.jpg",
    "url": "/cards/card002"
  },
  {
    "title": "card 3 title",
    "imageUrl": "/front-cover-landscape.jpg",
    "url": "/cards/card003"
  }
]

/cards/[cardId]/[sizeId]

This endpoint returns a single card identified by its id. It takes an optional route parameter sizeId - the sizing of a card affects its price.

• price is calculated by the multiplying the basePrice of the card by the priceMultiplier from the selected size. If no size is provided it should default to the basePrice. The basePrice is the amount in pence and the result should be formatted as a string e.g. "£2.00".

Expected JSON response from GET /cards/card001/gt:

{
  "title": "card 1 title",
  "size": "gt",
  "availableSizes": [
    {
      "id": "sm",
      "title": "Small"
    },
    {
      "id": "md",
      "title": "Medium"
    },
    {
      "id": "gt",
      "title": "Giant"
    }
  ],
  "imageUrl": "/front-cover-portrait-1.jpg",
  "price": "£4.00",
  "pages": [
    {
      "title": "Front Cover",
      "width": 300,
      "height": 600,
      "imageUrl": "/front-cover-portrait-1.jpg"
    },
    {
      "title": "Inside Left",
      "width": 300,
      "height": 600,
      "imageUrl": ""
    },
    {
      "title": "Inside Right",
      "width": 300,
      "height": 600,
      "imageUrl": ""
    },
    {
      "title": "Back Cover",
      "width": 300,
      "height": 600,
      "imageUrl": "/back-cover-portrait.jpg"
    }
  ]
}

Tools, Libraries and frameworks

An app skeleton is provided for your convenience. It consists of the following tools:

• Express
• Jest for unit/integration testing
• Supertest for integration tests
• TypeScript - If you're not familiar with TypeScript you can use JavaScript instead.

Scripts

Command	Description
yarn dev	run the server in development (watch) mode on port 7000
yarn test	run tests using Jest watch mode

Assessment

We will assess the task based on the following criteria:

• How clean, modular and extensible the code is
• Considerations for performance
• Approach to testing
• Knowledge of Node and its APIs
• Use of Git