There have been lots of talk about PRDs being dead and spec-driven development etc.

Here is how we are planning. We iterate with our team and agents on one plan document.

It starts with some of the key things in a PRD but shorter and to the point: goals, use cases, jobs to be done, differentiators, strategy, succcess.

Then, in the same document, we include architecture diagrams in excalidraw or mermaid.

Then we describe the implementation approach but without any code, the approach.

Goal is as short as possible while being thorough... usually a few pages.

Now, we have one unified document that we/agents can use to build. The agents use this plus a full testing plan plus the code. And we get much better results.

It is nice because a human can and will read a few page document and the agents will keep it up-to-date with what is implemented.