Joao F.

I build and ship complex software products — including AI-powered products, SaaS platforms, and data-heavy applications. I'm a senior AI engineer with a PhD and 2,500+ hours on Upwork, specializing in Python, Django/FastAPI, PostgreSQL, Rust, and AI/LLM systems. I can take ownership of a project end-to-end: AI/LLM: RAG, agents, tool use, structured outputs, document analysis, OpenAI/Anthropic integrations, retrieval and evaluation Backend: Python, Django, FastAPI, PostgreSQL, APIs, background processing and complex business logic SaaS: architecture, authentication, billing, integrations, data workflows and production deployment Data-heavy applications: calculations, imports/exports, reporting, document generation and automation Technical software: Rust, Tauri, PyQt and applications involving scientific or engineering data Infrastructure: Docker, AWS and Kubernetes Two recent examples are products I designed and built and now run in production. Fiscopia is a SaaS product for Portuguese freelancers working with international clients — it handles transaction imports, foreign-currency income, VAT, Social Security, IRS planning, tax deadlines, reporting and third-party integrations. ScientivoLab is lab operations software for small biotech and research labs, covering inventory with lots and expiry tracking, sample location history, equipment maintenance and calibration, and SOP versioning with approvals — organization-scoped, with role-based permissions, billing and a REST API. I've also worked with scientific instrumentation startups, building software at the intersection of engineering, science and hardware. What you get from me I don't just implement tickets. I'll help figure out what should actually be built, make pragmatic architectural decisions, push back when something is unnecessarily complicated, and stay involved through deployment and production. And while I work extensively with AI, I don't assume everything needs an LLM. Sometimes a conventional solution is more reliable, cheaper and easier to maintain. The goal is to build the right product, not to add AI for its own sake. Background PhD in Electrical Engineering — University of Southampton Top Rated Plus on Upwork 100% Job Success $100K+ earned on Upwork 2,500+ hours delivered Experience with startups and founder-led products Core stack: Python · Django · FastAPI · PostgreSQL · Rust · OpenAI · Anthropic · pgvector · Docker · AWS · Kubernetes · React · TypeScript If you're building a real product with meaningful technical complexity, send me a few sentences about what you're trying to build and where you're stuck.