Thinking on product truth, behavior specs, and building software teams can reason about.
Subscribe via RSSWhen an outsourcing engagement wraps up, product knowledge walks out the door. A living behavior spec keeps it in the codebase — not in someone's head.
AI can extract product logic from your codebase. Stewie builds a living behavior spec your whole team can read — no code, no docs, no waiting on engineers.
Product owners confirm behaviors. BAs clarify logic. QA knows what to protect. New hires onboard fast. Vendors skip reverse-engineering. One shared contract.
Leaders shouldn't need three meetings to verify whether a product decision was implemented correctly. A living behavior spec is the direct line.
Your agent ships code that passes review and still breaks a product promise. It is not a capability gap — it is the product context no rules file gives it.
Your repo has workflow instructions, session context, and feature specs. None of them answer what the product promises to do. That's the PBC layer.
Shipping fast with AI coding tools is genuinely good. The problem isn't the speed — it's what gets left behind. Product reasoning doesn't survive the vibe.
A .pbc.md file opens in VS Code, renders on GitHub, reads like any Markdown doc. Drop it into pbc.stewie.sh and the same file becomes navigable UI.
After hitting the same product knowledge gap across multiple SaaS products, I built an open Markdown spec for capturing what your product promises to do.
A field guide to the .pbc.md format — the structured blocks that make up a Product Behavior Contract: behaviors, triggers, outcomes, and provenance.
