Picture the merge request that lands at 5pm. The code works — probably. But there's a duplicate test file, an API shape nobody recognizes, coverage with no rationale, and nothing explaining why. The plan the AI wrote to build it? Gone — it lived on a laptop just long enough to ship. The reviewer can rubber-stamp it or reverse-engineer the intent from scratch. That's the hidden tax of vibe coding: fast to start, impossible to trust. And when every team improvises its own version, you don't get velocity — you get a dozen private dialects and no path a new engineer can pick up.

This talk is about closing that trust gap. We built a spec-driven workflow where the spec — not the prompt, not the ephemeral plan — is the single source of truth, human-approved before any code exists, with agents implementing and validating against it. Work arrives review-ready: a diffable spec a human signed off on, a documented reason for every kept test, and a clean trail from ticket to result. Specs are committed alongside the code, so intent lives on as durable documentation and can power drift detection on future changes.

Then a second idea changed the feel of the whole thing: the work doesn't have to start in the editor. We made it possible to kick off spec-driven development straight from Slack, where teams already align and decide. When the journey begins in a shared channel instead of a solo IDE session, the spec becomes a conversation the whole team can shape before code exists — review starts at the idea, not the merge request, and onboarding means pointing someone at a thread. Individual AI assistance becomes a collaborative team practice.

I'll walk through the six-stage, human-gated loop, both entry points in action, and the honest tradeoffs — repo bloat, how much structure is too much, and where a human still holds the pen. You'll leave with a blueprint for moving from untrustworthy plan mode to a durable, collaborative SDD practice you can standardize.