Web Fundamentals

API Design Best Practices: Pagination, Errors, Versioning & Type Safety

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mediumWeb Fundamentals

API Design Best Practices: Pagination, Errors, Versioning & Type Safety

Learn the interview-ready mental model, practical trade-offs, and production patterns for this web fundamentals topic.

Topic content

TL;DRGood APIs are stable, predictable, and easy to evolve. Prioritize cursor pagination, actionable errors, explicit versioning, and type safety.

High Signal

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30-Second Answerstart every interview with this

Great API design focuses on consumer experience, long-term maintainability, and safe evolution. Key areas include pagination strategy, meaningful error responses, versioning approach, and type safety between frontend and backend.

Pagination = how you serve large orders efficiently. Error handling = clear communication when something goes wrong. Versioning = updating the menu without confusing regular customers. Type safety = ensuring the kitchen and waiter always speak the same language.

Define Clear Contract

Implement Pagination & Errors

Version Safely

Add Type Safety

1Pagination Strategies

Offset-based for page navigation (admin tools). Cursor-based for infinite scroll and timelines (more stable under inserts/deletes).

2Error Response Design

Always return structured errors with machine-readable codes, human messages, and field-level details. Use standard HTTP status codes appropriately.

3API Versioning

URL path versioning is most explicit. Header versioning keeps URLs clean. Plan deprecation paths from day one.

4Type Safety Approaches

OpenAPI/Swagger for broad compatibility. tRPC for full-stack TypeScript. GraphQL for flexible, self-documenting contracts.

Key Takeaways

✓Choose pagination strategy based on UX (cursor for infinite scroll)
✓Design clear, actionable error responses with codes
✓Plan API versioning and deprecation from the start
✓Invest in type safety (OpenAPI, tRPC, or GraphQL)
✓Keep APIs predictable and easy to evolve
✓Balance flexibility with operational simplicity
✓Good APIs make frontend development faster and safer

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