I run an established SaaS platform and need a seasoned Python back-end developer who can give me 10–15 focused hours each week. The job is all about keeping things running smoothly rather than building big new features. You’ll dive into the existing codebase to patch bugs, tighten performance, and make small but meaningful API tweaks. Performance is my top priority. I specifically want measurable database optimizations and code-level efficiency improvements—think query plan tuning, smarter indexing, and refactoring any hotspots you uncover with profiling tools. When we touch the API, the work will be incremental: adjusting or extending current endpoints so the front-end team can ship without friction, plus updating tests and docs as you go. You should be comfortable reading production code, submitting clean pull requests, and explaining what changed and why. Familiarity with common Python frameworks (FastAPI, Django, Flask) and PostgreSQL is a bonus, but your ability to identify bottlenecks and ship safe fixes matters most. Each week you’ll deliver: • Pull requests covering the tickets we’ve agreed on • A brief changelog that highlights performance gains or behavioural adjustments • Updated unit tests to keep our CI green Acceptance criteria are straightforward: no regressions, CI passes, and the targeted queries or functions run noticeably faster—ideally 30 % or better. If you enjoy methodically improving mature code and can communicate clearly in async workflows, I’d like to work with you.