Since November 2025, I’ve built and run Voltura/HeatShield as a solo project. It’s a bilingual React 19 app with a TypeScript and Express 5 API backed by PostgreSQL, shipped to production with two LLM features.
While investigating external irradiance data, I found malformed lookup keys and a fallback that generated identical values across locations. Correcting the issue showed that the previous figures overstated savings by 13.5%; I moved validation to the parsing boundary so invalid data returns a typed 422 instead of a plausible number.
I grew the project’s test suite to 600+ tests and use mutation testing and CI to check changes. I also published TokenGuard, an MIT-licensed npm CLI for LLM cost auditing, and contributed fixes and reports to open-source projects.
