What's the Deal with GitHub Spec Kit

Summary

I get to finally write a bit about a project I was knee-deep in for the past month - GitHub Spec Kit. It’s a project born out of John Lam’s research in how to help steer the software development process with Large Language Models (LLMs) and make it just a tiny bit more deterministic. After all, we all know that vibe coding into production is just a monumentally shortsighted approach, but what’s the alternative?All of this thinking and more got encapsulated in an experiment around the concept of Spec-Driven Development (SDD) that we collectively shipped in the open on GitHub, called GitHub Spec Kit.Why specs #The first question I usually get around Spec Kit is - “Why bother?” If LLMs are essentially “roll of the dice” kind of technology, can’t you just vibe code a bunch of stuff together and call it a day?If you’ve used LLMs to vibe code anything, no matter how small, you know that the output can vary wildly. The prompt that you ran can produce a completely different result from the exact same prompt that your friend ran on a different computer that same day. LLMs are built like that - every time you ask it to do things, the little bits of sand in your computer start interacting with electrical signals and some complex math way out in the datacenter somewhere (unless you’re running things locally, of course) to predict the output. That means, by design, that said output will be, shall we say, variable.That’s not necessarily a bad thing - we came to terms with the fact that this is how the technology works. Yet, within our team we still posed the question - “Can we harness this tech to produce deterministically good software?” We think one potential route there is through specifications. We are actually not alone in this thinking.For those of you who are not product managers, specifications might mean different things. You also might’ve heard different terms thrown around in the same vein - PRDs, BRDs, CRDs, specs, and other fancy ways Silicon Valley tried everyone to...