Twelve years building software. Four of those leading engineering teams of 35+. Lately I write up what I find interesting. Rhythm is irregular, only when something is worth reading.
- llamaindex-embedding-churn. Reproducer for a two-bug interaction in
llama-index-corethat silently re-embeds unchanged content across half the fsspec backend ecosystem. Three-line fix filed upstream as PR #21462. Writeup. - ChatGPT LightSession. Chrome extension that trims long ChatGPT threads client-side. Currently at 50,000+ users and 4.8 stars, shipped without paid distribution. Chrome Web Store. Writeup.
- CodeGraph. Local MCP server I built for Claude Code. Pre-computes a tree-sitter call graph and exposes it through six tools. On a 484-file FastAPI benchmark: 59% fewer investigation tokens, 60% fewer turns, and 82 seconds less wall time, with file recall preserved at 100%. Writeup.
- 12 years software engineering. 4 of those leading teams of 35+.
- Built an AI SDR platform end-to-end as a solo founder (LangGraph, async workers, human-in-the-loop).
- Worked on a hybrid retrieval stack (vector + graph + keyword) and built its benchmarking pipeline, scored against LongMemEval and LoCoMo.
- UC Berkeley postgrad certificates in Machine Learning and AI, and Technology Leadership.
sebastiantirelli.com · LinkedIn · X / Twitter · tirelli@gmail.com