Harness Engineering
A harness that makes AI-driven development fast and safe at once
Context
I started Pervis owning every layer from the design phase on, which made engineering speed the same thing as business speed.
Agent-driven development is fast, but without guarantees on quality and consistency the review and rework costs eat the gains. I needed a system that delivered both at once.
How I solved it
- Designed the gates around baselines
- complexity, circular dependencies, migration integrity and more are pinned to baseline files, so existing debt passes while new violations are blocked
- Wired 26 hooks across 8 lifecycle points (edit, commit, compaction, exit) so an agent cannot route around the rules
- Structured what agents read: 17 domain rule documents plus per-branch session state, preserved across context compaction
- Split roles into 19 agents across three tiers (planning, execution, tooling), and isolated parallel work with worktrees and locks
- Watched spec-to-code drift on a nightly workflow, and cut runaway agent loops with a circuit breaker
- Wired incident response into one automated pipeline
- gather the context, find the cause, fix it, deploy
Result
- Shipped an epic-sized feature scoped at a month under standard estimation in five days
- The system carries the whole development process, which leaves designing and building the product as the work I actually do
- writing code, reviewing PRs, holding quality, keeping specs and conventions aligned
- Incidents and bugs are handled end to end without me, which is what keeps the service steady
- context gathered, fix made, deployed
- Used by the whole team, continuously
- 135 verification scripts, 26 hooks, 19 agents
- Pervis, built on this system, reached a PoC customer within 2 months of starting development, a paying one within 5, and its first full contract within 7
- the speed turning straight into a business timeline
Standard industry estimate1 month
Actual5 days