My day job is at a large tech company. Hundreds of engineering teams, and every one of them is somewhere different on AI adoption. Some are still treating coding agents as a curiosity. Some have quietly rebuilt their whole workflow around them. Most are in the messy middle, and watching that middle is where the idea for Penling came from. Spec-driven development has arrived, and I think it's the right idea. Tools like SpecKit and Kiro put the specification front and center to the coding workflow