API Design & Patterns

Complete guide to designing robust, scalable APIs—from requirements to production

95 minutes

10Detailed Sections

Senior Level

Before writing code, understand your API consumers. Identify use cases: who will call this API (mobile apps, web frontends, third-party integrations, internal services)?

What data do they need? What operations must they perform?

Define NFRs (Non-Functional Requirements): latency targets (p50, p95, p99), throughput (requests/sec), availability (SLO 99.9% vs 99.99%), consistency (strong vs eventual), security (authentication, authorization, data privacy).

Design principles for robust APIs: Simplicity—keep endpoints minimal; Consistency—use standard naming (plural nouns, hyphens); Evolvability—design for backward compatibility from day 1; Documentation—use OpenAPI/Swagger; Developer Experience—clear errors, examples, SDKs.

Real-world: Twilio designs APIs for developers first (great docs, SDKs); Stripe focuses on idempotency and retries; AWS uses consistent naming across hundreds of services.

Key Takeaways

Consumer Analysis: Identify who uses API (mobile, web, integrations) and what they need

NFRs: Define latency (p95 < 100ms), throughput (10k req/s), availability (99.9% SLO)

Design Principles: Simplicity, consistency, evolvability, documentation, developer experience

Backward Compatibility: Design for adding fields without breaking existing clients

Security Requirements: Authentication (OAuth, API keys), authorization (scopes), encryption

Real-world: Twilio (docs-first), Stripe (reliability), AWS (consistency at scale)

Visual Diagram

Requirements -> Use Cases -> NFRs -> Design Principles -> API Spec -> Implementation

All Tutorials Practice Questions

API Design & Patterns

Table of Contents

API Requirements Gathering & Design Principles

Key Takeaways

Visual Diagram

Foundations: REST, GraphQL, and gRPC

REST Best Practices: Resources, Verbs, and Conventions

Pagination Strategies: Offset vs Cursor

GraphQL Deep Dive: Schema, Queries, and Subscription

API Versioning Strategies

Authentication and Authorization Patterns

Rate Limiting and Idempotency

Error Handling, Monitoring, and SLO Tracking

Case Studies: API Design in Production