ℹ️ See my write-plan and implement-plan skills.

Update August 23, 2026: I’ve updated the skills. The updates are about the relationship between the plan file and a project’s standing documents (like CLAUDE.md). Details are in this comment on the write-plan gist and this one for implement-plan.

The pre-AI coding era: BDUF (big design up front) vs iterative planning

I spent the first 10 years or so of my career (going back to the 90s here, folks) in the Waterfall/BDUF era: long meetings discussing endless hypothetical scenarios, big planning documents covering months of work, missed deadlines, and deliverables that typically ended up misaligned with actual needs. The reasons for this frequent misalignment are now obvious, since our industry has matured since then (at least in some ways):

1. There was no feedback until we wheeled out our giant project at the end, and by then it was too late.
2. In planning, what people tell you they want is often not what they actually want or need (they may think they know, but since there’s no software yet for them to interact with, they’re guessing, and doing their best to answer all your planning questions).

This is what spawned the Agile movement, which started to gain traction in the early 2000s, and at the time it felt revolutionary. It turned Waterfall on its head, with short development and deliverable cycles and frequent feedback (Agile has unfortunately accreted its own layers of bureaucracy since then, but that’s another story).

The AI coding era: BDUF is back, but should it be?

In our new era of AI-assisted coding, BDUF is back: we can now generate planning documents and code faster and cheaper, so why not? You can develop your plan, walk away while AI works on it for a few hours, and then deliver. If what you delivered ends up needing changes, repeat the process. This is how the popular Superpowers skill for executing plans works (and most other AI planning skills I’ve seen): “Load plan, review critically, execute all tasks, report when complete.”