• Develop and maintain backend services and REST APIs (FastAPI, DRF, PostgreSQL) for customers, orders and reports. • Optimize PostgreSQL queries: EXPLAIN ANALYZE, indexing and removing ORM N+1 queries on heavy endpoints. • Integrate external APIs with timeouts, retries and error handling; Redis caching, Celery + RabbitMQ background tasks. • Cover critical business logic with unit and integration tests (pytest); ship via Docker and GitHub Actions CI/CD. • Join code reviews and technical discussions; work with frontend, QA and product, and help on the React client. • Use Claude Code and Cursor daily to speed up development, analyze unfamiliar code, review and debug.

• Built business logic and REST APIs on DRF + PostgreSQL using OOP and Service Layer / Repository patterns. • Integrated payment gateways and secure webhooks (signature checks, idempotent handlers, retry logic). • Fixed production bugs with QA in Agile/Scrum; refactored existing code via Git feature branches and PRs.