keyvec's personal site: writing on LLM systems, data engineering, retrieval, agents, and evaluation, plus the projects behind it.https://keyvec.com/https://keyvec.com/posts/retrieval-eval-that-survives-index-changes/https://keyvec.com/posts/retrieval-eval-that-survives-index-changes/Notes on building a small, fixed question set for a RAG system so it measures correctness instead of quietly agreeing with whatever the current index returns.Thu, 02 Jul 2026 00:00:00 GMThttps://keyvec.com/posts/evidence-first-llm-systems/https://keyvec.com/posts/evidence-first-llm-systems/A working note on the question this site keeps returning to: what evidence should technical work leave behind, and how to design pipelines so the evidence is a byproduct, not a chore.Tue, 16 Jun 2026 00:00:00 GMT