Daniel KliewerThe book

Systems

Twelve systems, and the problem each one was built to answer.

These are not portfolio pieces. Each one exists because a specific failure was intolerable: an agent that could act without permission, a retrieval system that could not tell a claim from a passage, a creative tool that reported success while doing nothing.

Maturity labels describe the code, not the ambition. Repository signals are a dated snapshot read on 25 October 2026 — a last-commit date and a count of test files. They are not benchmarks and not adoption figures.

Implementation · 10