Notes from the spine

Long-form on the metaphor, the routing table, and the benchmarks.

Working notes on building Spine. The product, the engineering, and the parts where the abstraction leaks. RSS.

April 26, 20266 min read— engineering
Pioneer benchmarks — when 80ms beats 530ms
Why we replaced an LLM round-trip with a locally hosted GLiNER2 model, what we measured, and what we learned about being honest with benchmarks.
April 25, 20266 min read— engineering
Routing model choice by surface — how we use Opus, Sonnet, and Haiku in one product
Spine routes every Claude call to the smallest model that can do the job. Here is the routing table, the reasoning, and the cost numbers.
April 22, 20266 min read— metaphor
Why a novel deserves a git log
A literary critic's mental model and a senior engineer's mental model are the same shape. Spine makes that shape visible.

Notes — Spine · Spine