I wrote my last PRD six months ago. Twelve pages, three days of work, two engineers read it. One of them asked me to just show him what I meant. So I built a working prototype in 45 minutes and showed them. They shipped it in a week, based on the prototype, not the document.
That is when it clicked. The document was never the point. Alignment was. And a prototype people can click through aligns a team far faster than a spec they have to read and interpret.
Why the PRD existed at all
PRDs made sense when building took forever and cost a ton. If shipping something takes three months, you had better be sure it is right before you start. The PRD was a contract: we agreed to this, and here is why it matters.
Building is not expensive anymore. A PM with AI can prototype in an hour. The cost of being wrong dropped from three months of engineering to one afternoon of my time. When being wrong is cheap, you do not need a twelve-page insurance policy against it. You need to learn faster.
What replaces it
Four things, and none of them is a long document.
The prototype. Something you can click, something that actually works. No interpretation gaps.
The one-pager. Strategic context: why we are building this, who uses it, how we measure success. One page forces you to be clear. Twelve pages is where ideas go to hide.
The recording. A five-minute Loom walking through the prototype. Stakeholders watch at 2x and get it.
The conversation. Thirty minutes with engineering. Show the prototype, talk feasibility, write down decisions in three bullets. Done.
But what about the hard stuff
"Simple features do not need PRDs, complex ones do." I hear that constantly, and it is backwards. Complex features need more prototyping, not more pages. If it is too complex to prototype, it is too complex to build. Break it into pieces until each one can be prototyped and tested on its own.
The worst features I have seen shipped had the most detailed PRDs. The document became a shield: we specified this exactly. Yeah. You specified the wrong thing exactly.
If your org still requires PRDs, do not quit them overnight. Build a prototype alongside the next one. When your team says the prototype was more useful, drop the PRD on the feature after that. Pick your next feature and build it before you write it.