KaratChallenge

The objecive of this repo is to:

• Collect transaction and authorization data from Stripe
• Build the necessary backend APIs to populate the necessary data in the provided design.

Getting Started

1. Clone this repo git clone https://github.com/IanArko/KaratChallenge.git
2. Setup packages: npm install
3. Set env variables in your shell:

export PORT=<DESIRED_PORT>
export TEST_MODE=< ON == 1 and OFF = 0 >
export STRIPE_SECRET_KEY=< YOUR_KEY >
export STRIPE_TEST_SECRET_KEY=< YOUR_KEY >

4. Start the server and have fun. npm start

Testing Notes

The main eendpoints are the following:

1. yourdomain/api/stripe/cards/:cardID
2. yourdomain/api/stripe/cardholders/:cardholderID
3. yourdomain/api/stripe/transactions/:cardID
   • Query Params: limit (defaults to 25), starting_after (for pagination)
4. yourdomain/api/stripe/authorizations/:cardID
   • Query Params: limit (defaults to 25), starting_after (for pagination)
5. yourdomain/hooks/stripe

Design Questions

• How else might you have improved your solution given more time?
  • See "Architecture Improvements" below.
• Feedback
  • Approximately how many hours did you spend on this challenge?
    • Overall, I spent about 12 hours on this challenge. Most of my time went to reading documentation and thinking about add-ons that I could include to make the challenge more interesting.
  • What did you find most interesting / rewarding about this challenge?
    • I had the most fun learning Express and thinking about ways to improve the project. Normally I would have used AWS API gateway with lambda functions, but I wanted to try something new.
  • What did you find least interesting / rewarding about this challenge?
    • The only thing I didn't like about the project was that there wasn't a super meaningful way to do a deployment. I didn't want to spend time doing a deployment since it wouldn't improve the core functionality or the testability of the project.

Improvements

• Write tests with Jest for more consistent testability.
• Add dotenv to make setup easier
• Deploy Container (Maybe use Amazon ECR and an ECS cluster)
• Add Auth and make it so users can only access their own resources
  • A stateless architecture would allow the most flexibility for multi-region support, but if we only have one instance, we'll see a higher overhead
• Add an API Gateway for request throttling
• Add multiple Express severs in different regions with a load balancer for improved access
  • NOTE: For this use case, we aren't as worried about the number of requests. Say we have at most 50k users, but an Express app can handle ~10k concurrent connections. Having multi-region support would allow 2 main benefits. 1) Improved access time based on geography. 2) Higher fault tolerance in case a region goes down.
• Extend multi-card functionality
  • It didn't seem like the Cardholder object contained which cards were associated with the Cardholder. We may need to create a db to keep track of the user data and which cards are associated with a specific user.

Design Notes

1. The paths are verbose for this application. I intended to make this design so that new resources could easily be added in the future.
2. The endpoints were designed to be as close to stripe's as I could without bloating the design with features that weren't needed for our specific application.