backend-development

Backend Development Skill

Production-ready backend development with modern technologies, best practices, and proven patterns.

When to Use

• Designing RESTful, GraphQL, or gRPC APIs
• Building authentication/authorization systems
• Optimizing database queries and schemas
• Implementing caching and performance optimization
• OWASP Top 10 security mitigation
• Designing scalable microservices
• Testing strategies (unit, integration, E2E)
• CI/CD pipelines and deployment
• Monitoring and debugging production systems

Technology Selection Guide

Languages: Node.js/TypeScript (full-stack), Python (data/ML), Go (concurrency), Rust (performance) Frameworks: NestJS, FastAPI, Django, Express, Gin Databases: PostgreSQL (ACID), MongoDB (flexible schema), Redis (caching) APIs: REST (simple), GraphQL (flexible), gRPC (performance)

See: references/backend-technologies.md for detailed comparisons

Reference Navigation

Core Technologies:

• backend-technologies.md - Languages, frameworks, databases, message queues, ORMs
• backend-api-design.md - REST, GraphQL, gRPC patterns and best practices

Security & Authentication:

• backend-security.md - OWASP Top 10 2025, security best practices, input validation
• backend-authentication.md - OAuth 2.1, JWT, RBAC, MFA, session management

Performance & Architecture:

• backend-performance.md - Caching, query optimization, load balancing, scaling
• backend-architecture.md - Microservices, event-driven, CQRS, saga patterns

Quality & Operations:

• backend-testing.md - Testing strategies, frameworks, tools, CI/CD testing
• backend-code-quality.md - SOLID principles, design patterns, clean code
• backend-devops.md - Docker, Kubernetes, deployment strategies, monitoring
• backend-debugging.md - Debugging strategies, profiling, logging, production debugging
• backend-mindset.md - Problem-solving, architectural thinking, collaboration

Key Best Practices (2025)

Security: Argon2id passwords, parameterized queries (98% SQL injection reduction), OAuth 2.1 + PKCE, rate limiting, security headers

Performance: Redis caching (90% DB load reduction), database indexing (30% I/O reduction), CDN (50%+ latency cut), connection pooling

Testing: 70-20-10 pyramid (unit-integration-E2E), Vitest 50% faster than Jest, contract testing for microservices, 83% migrations fail without tests

DevOps: Blue-green/canary deployments, feature flags (90% fewer failures), Kubernetes 84% adoption, Prometheus/Grafana monitoring, OpenTelemetry tracing

Quick Decision Matrix

Need	Choose
Fast development	Node.js + NestJS
Data/ML integration	Python + FastAPI
High concurrency	Go + Gin
Max performance	Rust + Axum
ACID transactions	PostgreSQL
Flexible schema	MongoDB
Caching	Redis
Internal services	gRPC
Public APIs	GraphQL/REST
Real-time events	Kafka

Implementation Checklist

API: Choose style → Design schema → Validate input → Add auth → Rate limiting → Documentation → Error handling

Database: Choose DB → Design schema → Create indexes → Connection pooling → Migration strategy → Backup/restore → Test performance

Security: OWASP Top 10 → Parameterized queries → OAuth 2.1 + JWT → Security headers → Rate limiting → Input validation → Argon2id passwords

Testing: Unit 70% → Integration 20% → E2E 10% → Load tests → Migration tests → Contract tests (microservices)

Deployment: Docker → CI/CD → Blue-green/canary → Feature flags → Monitoring → Logging → Health checks

Implementation Principles

Avoid over-engineering. Only make changes directly requested or clearly necessary. Keep solutions simple and focused. Do not add features, refactor code, or make improvements beyond what was asked. Start with a monolith and split to microservices only when needed.

Read and understand relevant files before proposing code edits. Do not speculate about code you have not inspected.

Resources

• OWASP Top 10: https://owasp.org/www-project-top-ten/
• OAuth 2.1: https://oauth.net/2.1/
• OpenTelemetry: https://opentelemetry.io/