Rippling
Medium
Software EngineerScale a rules engine for high traffic
System Design
20
0
February 12, 2026
API Design Interview Questions
API design questions test your ability to create clean, scalable, and secure interfaces between services and clients.
Expect discussions on REST vs GraphQL, pagination strategies, rate limiting, versioning, and authentication patterns.
Interviewers want to see practical design sense, not just theoretical knowledge of HTTP methods.
935Questions
167Companies
Easy 44 • Medium 1 • Hard 468Difficulty mix
Common API design interview patterns
- REST resource modeling and URL structure
- GraphQL vs REST trade-offs
- Cursor-based vs offset pagination
- Rate limiting and throttling strategies
- API versioning approaches
- Idempotency for safe retries
- Authentication and authorization patterns (OAuth, JWT, API keys)
API design interview questions
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Anthropic
Hard
Software EngineerDesign production-ready dedup service
System Design
15
0
September 6, 2025
Rippling
Hard
Software EngineerDesign a user behavior tracking system
System Design
34
0
February 11, 2026
Netflix
Medium
Software EngineerDesign ad frequency capping
System Design
27
0
April 15, 2026
OpenAI
Hard
Software EngineerDesign a crossword puzzle solver system
System Design
31
0
February 11, 2026
Databricks
Hard
Software EngineerDesign a KV store with QPS API
System Design
13
0
February 4, 2026
Instacart
Hard
Software EngineerDesign product catalog service
System Design
29
0
August 4, 2025
Harvey AI
Hard
Software EngineerDesign a production file storage service
System Design
21
0
September 6, 2025
Scale AI
Easy
Software EngineerDesign an LLM API pipeline
ML System Design
20
0
March 17, 2026
Roblox
Hard
Software EngineerDesign sliding-window rate limiter with multi-keys
System Design
24
0
July 16, 2025
Databricks
Medium
Software EngineerDesign a stock order manager
System Design
24
0
April 12, 2026
DoorDash
Medium
Software EngineerDesign a donations service with 3-day rolling totals
System Design
19
0
December 16, 2025
Coinbase
Hard
Software EngineerDesign a bank account ledger
System Design
24
0
September 6, 2025
Rippling
Hard
Software EngineerDesign a hotel search and booking system
System Design
19
0
December 8, 2025
Jane Street
Easy
Software EngineerValidate order book data across multiple databases
System Design
17
0
December 15, 2025
Axon
Medium
Software EngineerDesign fulfillment truck routing and inventory system
System Design
18
0
March 1, 2026
Airbnb
Medium
Software EngineerDesign a booking system
System Design
20
0
February 12, 2026
Coinbase
Medium
Software EngineerDesign account system with cashback
System Design
89
0
July 29, 2025
Parafin
Hard
Software EngineerDesign loan application system
System Design
31
0
August 4, 2025
Meta
Hard
Data EngineerDesign batch and streaming ETL architecture
System Design
25
0
July 15, 2025
Common mistakes with API design
- Overusing POST for operations that should be GET
- Not designing for backward compatibility
- Exposing internal implementation details in the API surface
- Ignoring error response formats and status codes
- Not considering rate limiting from the start
How API design questions are evaluated
Design for the consumer, not the implementation.
Show awareness of backward compatibility and versioning from day one.
Discuss security considerations naturally as part of the design.