Part-Time Senior Full-Stack Engineer (Python/FastAPI + React)

We're a US-based architecture firm with our own internal, AI-powered operations platform, and we need a part-time senior full-stack engineer to help maintain it and build new features. It's live and in daily use, so we're not starting from scratch. ABOUT THE ROLE Around 10 hours per week, ongoing (6+ months). Roughly half the work is maintenance and debugging (keeping data syncs and integrations healthy, fixing production issues), and half is building features (new API endpoints and services, dashboards and reporting, a read-only client view, financial/budget tracking). Every change goes through a pull request with automated code review. OUR STACK - Backend: Python 3.11, FastAPI, SQLAlchemy, Alembic - Frontend: React + TypeScript, Vite, Tailwind - Database: PostgreSQL (Supabase), including row-level security - AI/LLM: OpenAI / Anthropic / Gemini APIs for text extraction and classification - Integrations: chat, email, meeting-transcript, file-storage, and accounting systems - Workflow: GitHub, pull requests, CI checks, AI code review WHAT WE'RE LOOKING FOR - 5+ years of full-stack experience, including production systems with live third-party integrations - Strong Python + FastAPI (async, SQLAlchemy, database migrations) - Solid React + TypeScript; comfortable building a data table and wiring up API calls without hand-holding - PostgreSQL fluency: writing migrations, debugging queries, row-level security - A real debugging instinct; a lot of this job is figuring out why something broke - Experience with LLM APIs (prompts, handling failures, evaluating output quality) - Strong written English, since most coordination is asynchronous Nice to have: QuickBooks or accounting-data experience, Supabase, Slack API, or a background in architecture/construction. HOW WE WORK We're a small team. Two non-technical owners direct the work, and you'd be our dedicated engineer working alongside our AI coding tools. You're the experienced human judgment on architecture, debugging, and quality. Work is mostly asynchronous; you'd just need about 2 hours of daily overlap somewhere within our 7am-9pm US Pacific working window, so an evening or early-morning overlap works fine. Requests usually come in plain English, not detailed tickets, so we need someone who can investigate, propose an approach, and ship. PLEASE DON'T APPLY IF - You need every task fully spec'd before you start - You want to re-architect everything (the system has deliberate design rules to work within) - You treat automated code review as a nuisance rather than a tool TO START We'll begin with a small paid trial task so we can both see how it goes before committing to ongoing hours. If it's a good fit, this becomes a long-term part-time role.