Python/FastAPI Multi-Tenant Backend Enhancements

My SaaS platform already runs on FastAPI with SQLAlchemy 2.0, Alembic, and Postgres. The foundations are solid, yet several partially built features still need to reach production-ready quality, and each change must respect strict multi-tenant data isolation... (Budget: £250 - £750 GBP, Jobs: Backend Development, CI/CD, FastAPI, Git, GitHub, PostgreSQL, Python, Software Development)