• .Net Core
• 15
• October-12-2025
• by Ihsan Ullah

API Design Patterns: CRUD, RPC, and Beyond

1. CRUD (Create, Read, Update, Delete)

• Concept: Mirrors database operations, usually over HTTP with REST.

• Structure:

  • POST /users → Create

  • GET /users/1 → Read

  • PUT /users/1 → Update

  • DELETE /users/1 → Delete

• Strengths: Simple, predictable, aligns with resources.

• Weaknesses: Limited for complex workflows (e.g., “approve loan” doesn’t map neatly to CRUD).

2. RPC (Remote Procedure Call)

• Concept: Exposes functions or procedures directly.

• Structure: Method-style endpoints.

  • POST /sendEmail

  • POST /transferFunds

• Strengths: Straightforward for action-based tasks.

• Weaknesses: Can become hard to manage with many verbs; less resource-oriented.

3. REST (Representational State Transfer)

• Concept: Resource-centric, stateless, uses HTTP verbs and URIs.

• Principles: Resources identified by URL, actions via standard verbs, hypermedia links possible.

• Strengths: Clear conventions, web-native, cacheable.

• Weaknesses: Over-fetching or under-fetching of data.

4. GraphQL

• Concept: Query language for APIs where the client specifies exact data needed.

• Structure: Single endpoint (/graphql), queries define shape of response.

• Strengths: No over/under-fetching, good for mobile apps.

• Weaknesses: More complex server implementation; caching harder.

5. gRPC (Google RPC)

• Concept: High-performance binary protocol built on HTTP/2 with Protocol Buffers.

• Structure: Contract-first (proto files), strongly typed methods.

• Strengths: Fast, efficient, supports streaming.

• Weaknesses: More complex debugging; not human-readable.

6. Event-Driven APIs (Pub/Sub, Webhooks, WebSockets)

• Concept: Instead of request/response, the server pushes updates.

• Examples: Webhooks on payment success, WebSockets for chat.

• Strengths: Real-time, decoupled.

• Weaknesses: Harder to guarantee delivery and order.

7. Composite / BFF (Backend for Frontend)

• Concept: One API tailored per client (mobile, web, IoT). Aggregates multiple services.

• Strengths: Optimized responses, shields clients from complexity.

• Weaknesses: More maintenance if many client-specific backends.

Summary Table