Intermediate~4h
API Design in System DesignInterview Readiness Check
REST best practices, versioning, rate limiting, auth patterns, GraphQL, gRPC.
restapigraphqlgrpcversioningrate-limitingoauthjwtidempotency
Learning path
Try a sample question
PATCH /orders/42 with body {"quantity": "quantity + 1"} is called twice due to a network retry. Which property does this violate and why?
A.Idempotency — applying the operation twice produces a different result than applying it once
B.Cacheability — PATCH responses cannot be cached
C.Safety — it reads server state without the client knowing
D.Statelessness — the server must remember the previous value
Sign up free to take the full check and see the answer with an explanation.
What this module tests
- Conceptual understanding of api design fundamentals
- Trade-offs and design decisions in real system scenarios
- rest and api — applied knowledge
- Interview-style reasoning and explanation quality
Free to start
Take the API Design check →
10 questions · Dimension scoring · AI coach feedback · Shareable result
Test your knowledge — free →No credit card · Takes 10–15 min
Frequently asked questions
- What does the API Design check test?
- The check covers rest best practices, versioning, rate limiting, auth patterns, graphql, grpc. Questions span beginner to advanced difficulty and test both conceptual understanding and practical trade-off reasoning.
- What keywords should I know for API Design?
- Key concepts include: rest, api, graphql, grpc, versioning, rate-limiting, oauth, jwt, idempotency. These frequently appear in system design interviews at product and infrastructure companies.
- How many questions are in the check?
- Each check has 10 questions — a mix of MCQ and short-answer. You get scored by dimension (e.g., scalability, consistency) so you know exactly where to focus.
- How long does it take to study API Design?
- Most engineers spend around 4 hours on this module. The check itself takes about 10–15 minutes. You can retake it up to 3 times per day.
- What prerequisite knowledge do I need before API Design?
- API Design builds on Fundamentals. Complete those first for the best results.
- Is rest, api, graphql covered?
- Yes. The API Design module covers rest, api, graphql among other key concepts. The check includes questions that reflect real system design interview patterns.