Engineering write-ups
How the systems are built.
Systems I build and run myself, written up for engineers. Each one covers a problem that was genuinely complex, the constraints that shaped the solution, and the approaches I considered and rejected.
Retrieval-augmented generation
Building a RAG pipeline that can show its work
Read the write-up →Answering questions about federal nursing-home regulation, where a confident wrong answer is worse than no answer. Query rewriting, hybrid retrieval, rank fusion, two passes of deduplication, and an answerability check that lets the system decline.
Retrieval architecture · Prompt-injection defense · Evaluation
Security & compliance engineering
Provenance and egress control for health data
Read the write-up →A hash-chained ledger that records what crossed each trust boundary, who it crossed for, and what came back. Field-level encryption that keeps search working, and offboarding that reaches into six-year-old backup snapshots.
Tamper-evident audit · Field encryption · Boundary design
Clinical rules automation
Encoding CMS care-management rules as a testable system
Read the write-up →Eight overlapping Medicare care-management programs, each with its own eligibility, time thresholds, and rules about which others it can coexist with. Encoded as cited data rather than buried in conditionals.
Rules as data · Regulatory citation · Eligibility modeling