# Python Backend Architecture Review Checklist

This checklist serves as a quick reference for conducting comprehensive architecture reviews.

## System Architecture

- [ ] Architecture style matches scale and complexity
- [ ] Service boundaries are well-defined
- [ ] Communication patterns are appropriate
- [ ] No unnecessary over-engineering
- [ ] Single points of failure identified and addressed
- [ ] Dependency management is clear
- [ ] Framework choice is justified (FastAPI/Django/Flask/etc.)
- [ ] Async patterns are properly utilized where needed

## Database Architecture

- [ ] Database type selection is appropriate
- [ ] Schema is properly normalized/denormalized
- [ ] Indexes are strategically placed
- [ ] Sharding/partitioning strategy exists if needed
- [ ] Read replicas planned for scale
- [ ] Caching layer is implemented
- [ ] Connection pooling is configured
- [ ] N+1 query issues are prevented
- [ ] ORM choice is appropriate
- [ ] Migration strategy is defined
- [ ] Backup and DR plans exist

## API Design

- [ ] API design pattern is consistent (REST/GraphQL/gRPC)
- [ ] Endpoints follow naming conventions
- [ ] Versioning strategy is defined
- [ ] Authentication/authorization is implemented
- [ ] Rate limiting exists
- [ ] API documentation is auto-generated
- [ ] Error handling is consistent
- [ ] Pagination is implemented
- [ ] Input validation uses Pydantic or similar
- [ ] OpenAPI/Swagger documentation exists

## Security

- [ ] Authentication mechanism is secure (JWT/OAuth2)
- [ ] Authorization model is well-defined (RBAC/ABAC)
- [ ] CORS is properly configured
- [ ] CSRF protection is enabled where needed
- [ ] Data is encrypted in transit (HTTPS/TLS)
- [ ] Data is encrypted at rest where needed
- [ ] Secrets management solution exists
- [ ] SQL injection is prevented (parameterized queries)
- [ ] XSS protections are in place
- [ ] Security headers are configured
- [ ] Dependency scanning is automated
- [ ] Password hashing uses bcrypt/argon2
- [ ] Audit logging is implemented
- [ ] Rate limiting prevents abuse
- [ ] Input sanitization is thorough

## Scalability & Performance

- [ ] Scaling strategy is defined (horizontal/vertical)
- [ ] Load balancer is configured
- [ ] Auto-scaling rules exist
- [ ] Caching strategy is multi-layered
- [ ] Background jobs use queue system (Celery/RQ)
- [ ] Long-running tasks are async
- [ ] Database connection pooling is optimized
- [ ] ASGI server is production-ready
- [ ] GIL limitations are addressed
- [ ] Performance monitoring is in place
- [ ] Load testing has been conducted

## Observability

- [ ] Structured logging is implemented
- [ ] Log aggregation is configured
- [ ] Metrics are collected (Prometheus/StatsD)
- [ ] Distributed tracing exists (OpenTelemetry)
- [ ] Error tracking is configured (Sentry)
- [ ] Health check endpoints exist
- [ ] Alerting rules are defined
- [ ] Performance baselines are established
- [ ] Business metrics are tracked
- [ ] Dashboards are created

## Deployment & Infrastructure

- [ ] Dockerfile is optimized (multi-stage)
- [ ] Container orchestration is configured
- [ ] CI/CD pipeline is automated
- [ ] Environment parity exists (dev/staging/prod)
- [ ] Infrastructure as Code is used
- [ ] Deployment strategy is safe (blue-green/canary)
- [ ] Rollback procedure is defined
- [ ] Configuration is externalized
- [ ] Secrets are managed securely
- [ ] Dependencies are pinned and managed (Poetry/PDM)

## Code Organization

- [ ] Project structure is clear and logical
- [ ] Module boundaries are well-defined
- [ ] No circular dependencies exist
- [ ] Dependency injection is used appropriately
- [ ] Configuration management is centralized
- [ ] Type hints are used throughout
- [ ] Tests are well-organized (pytest)
- [ ] Code follows PEP 8 standards
- [ ] Linting/formatting is automated (Ruff/Black)

## Resilience

- [ ] Retry logic exists for external calls
- [ ] Circuit breakers protect external services
- [ ] Timeouts are configured appropriately
- [ ] Graceful degradation is implemented
- [ ] Error handling is consistent
- [ ] Dead letter queues exist
- [ ] Bulkhead patterns separate concerns
- [ ] Rate limiting protects resources

## Testing

- [ ] Unit tests exist (>80% coverage)
- [ ] Integration tests cover critical paths
- [ ] API tests validate contracts
- [ ] Load tests verify performance
- [ ] Security tests check vulnerabilities
- [ ] Test fixtures are reusable
- [ ] Mocking is used appropriately
- [ ] CI runs tests automatically

## Documentation

- [ ] API documentation is complete
- [ ] Architecture diagrams exist
- [ ] Setup instructions are clear
- [ ] Configuration is documented
- [ ] Deployment process is documented
- [ ] Code has docstrings
- [ ] README is comprehensive
- [ ] Contributing guidelines exist

## Compliance & Standards

- [ ] GDPR compliance addressed if applicable
- [ ] HIPAA compliance addressed if applicable
- [ ] SOC 2 requirements met if applicable
- [ ] Data retention policies defined
- [ ] Privacy policies implemented
- [ ] Audit trails exist
- [ ] 12-Factor App principles followed