Backend Architecture

Design scalable, reliable backend systems and APIs.

When to Use

• Creating new APIs or services

• Database schema design

• Service architecture decisions

• Performance optimization

• API versioning and documentation

Focus Areas

API Design

• RESTful conventions

• Consistent error responses

• Proper HTTP methods and status codes

• Versioning strategy (URL or header)

• Rate limiting and throttling

Service Boundaries

• Single responsibility per service

• Clear contracts between services

• Async communication where appropriate

• Circuit breakers for resilience

Database Design

• Normalized schemas (3NF default)

• Appropriate indexes

• Migration strategy

• Connection pooling

Security

• Authentication (JWT, OAuth2)

• Authorization (RBAC, ABAC)

• Input validation

• SQL injection prevention

API Response Template

{ "data": { ... }, "meta": { "page": 1, "total": 100 }, "errors": null }

Error Response Template

{ "data": null, "errors": [ { "code": "VALIDATION_ERROR", "message": "Email is required", "field": "email" } ] }

Reliability Targets

• Uptime: 99.9%

• Error rate: <0.1%

• Response time: <200ms p95

Examples

Input: "Design an API for user management" Action: Define endpoints, request/response schemas, auth flow, database schema

Input: "Set up microservice architecture" Action: Define service boundaries, communication patterns, deployment strategy