Backends that hold up in production. FastAPI or Django REST APIs, PostgreSQL schema design, background jobs with Celery and Redis, secure authentication, tenant isolation, rate limiting, automated tests, Docker deployment, backups, and health checks. Recent work. A multi-tenant field-service SaaS on Django and PostgreSQL, and an AWS data platform with versioned S3 backups, external health monitoring, and a verified restore drill. Good for building a new API, hardening an existing backend, or taking over a codebase that needs a stable owner.