160 cards
This deck introduces the core concepts behind API testing, starting with the basics of what it is and why it matters, then moving into the different layers of testing — from unit tests to full integration tests. You'll work through key ideas like contracts, happy-path versus negative tests, response shape validation, idempotency, authentication, authorization, and rate limiting. Each card is designed to build a clear mental model of how APIs are tested in practice and what makes a test suite genuinely useful rather than just superficial.
The deck is well suited for software developers who want to write more reliable services, QA engineers who are getting started with API-level testing, and students or job seekers preparing for technical interviews where testing concepts come up. Even if you have some experience with APIs, going through these cards is a good way to make sure your vocabulary and understanding of testing principles are sharp and consistent.
Because many of these concepts only really click when you see them in action, try to connect each card to a real API you've worked with or used — for example, think about where you've seen a 429 status code or a detailed validation error message. When reviewing, space your sessions out over a few days rather than cramming everything at once; the ideas layer on each other, and giving your brain time between sessions helps the terminology around contracts, idempotency, and edge cases move from short-term memory into something you can actually apply.