DIV-1 — this portfolio, built as a production AI system
LLM systems · Evaluation · Full-stack · 2026Problem
A portfolio that recruiters and engineers can question like a model has to be honest, cheap and dependable: it must never invent a claim, must keep working when models are rate-limited, and must not cost real money per visitor.
Approach
A deterministic router — keyword rules plus BM25 retrieval over a verified dossier — picks typed answer cards; a model only narrates over exactly those facts, raced across providers with a spend cap. Every answer records the facts it used, so a cached answer is invalidated only when one of its facts changes. Injection attempts are screened before any model; figures in model output are checked against the dossier. Built with evals in CI, an MCP server for AI screeners, and first-party analytics in Neon Postgres.
Results
72/72 golden questions
routed correctly, plus 37/37 prompt-injection cases — enforced in CI on every push
$0 for most answers
presets, honest absences and cached repeats need no model; a narrated answer costs about $0.0002
Per-fact cache invalidation
answers are invalidated only when a fact they cited changes — the EpiCache idea, running live
Queryable by AI agents
an MCP server, llms.txt and a typed dossier.json, so screening assistants read verified data
How it works
Question
console · API · MCP
Injection screen
before any model
Router
rules + BM25 over the dossier
Typed answer cards
exact, always
Narration if needed
model race · number tripwire
Recorded in Neon
answer · trace · per-fact cache