Writing
16 posts · tagged architecture · oldest Mar 2025
- Six hundred lines or it does not shipA 2,313-line orchestrator with a 1,073-line function is maintainable by a human with an IDE and unmaintainable by an agent. The refactor whose acceptance criterion was an agent behaviour, the CI guard that enforced it — and the fact that the guard is red as I write this.agentsarchitecturerefactoring10 min
- I built a time machine, then deleted half of itA retrospective on the deletions. Four timeline verbs, parallel variants in git worktrees, a record mode and four branch families — two cleanup specs removed almost all of it, including, awkwardly, the feature whose existence justified the first round.gitproductarchitecture10 min
- Driving the Agent SDK: permissions, hooks and capsA stage is one query() call. The five options that define what an autonomous agent is allowed to do, the four hooks that make an unattended run watchable, and an honest account of what bypassPermissions actually means.agentsaiarchitecture8 min
- One authority, three counters: deriving state from git refsNaming a source of truth is the easy half. The hard half is naming the moment every other view gets rebuilt from it — and the run where a UI, a state file and a git history gave three different answers to "how much of this is built".agentsdebuggingarchitecture9 min
- Git as the databaseEvery stage commits, the run is reconstructable from refs alone, and the app owns exactly two branch families. Why an autonomous builder should store its work in the versioning system its users already have — and what that choice costs at review time.gitarchitectureagents9 min
- Your test suite bills by the tokenTwenty minutes and real dollars to verify a two-line UI change. A pluggable agent backend, a mock that refuses to improvise, and checkpoint replay took it to sixty seconds and zero — plus an honest account of what the mock does not buy you.agentstestingarchitecture9 min
- Structured handoffs, and what the model is still allowed to decideWhen one agent hands work to the next, prose is the wire protocol — and a catastrophically bad one. The manifest that made feature selection cost zero tokens, and the line between what a schema pins down and what genuinely needs judgement.agentsaiarchitecture8 min
- Nine stages, nine amnesiacs: context isolation as an architectureDex never lets a session get long enough to rot. Every stage is a brand new agent with an empty context window, state travels through the filesystem, and the unit of everything — execution, resume, storage, the UI — is the stage. Including what that costs.agentsaiarchitecture9 min
- Three pillars, and what each one is missingDex is not a new idea. It is three existing ideas — a bash loop, a spec workflow, and an SDK — each of which is most of an autonomous coding system and none of which is all of it. The interesting part is the shape of the holes.agentsaiarchitecture9 min