The longest PRD I ever wrote was also the least useful one. It covered every edge case I could think of, and as far as I can tell nobody got past page two.
Engineers looked for the screens. Design looked for the flows. Leadership read the title and the date. All the reasoning sat in the middle, and a few weeks later someone asked a question in standup that the document had answered in detail.
These days I try to keep the core of a PRD to about one page and link out to anything longer. I want the team to understand the problem and the decision. I'm not trying to write a contract.
What the document needs to answer
A good product requirements document lets someone answer three questions without booking a meeting:
- Why are we doing this now?
- What's in this version, and what isn't?
- How will we know it worked?
If those are clear, people make small decisions on their own. If they aren't, every gap comes back to you as a Slack message.
Atlassian's guide to product requirements says something similar: keep it lightweight and aim for shared understanding over exhaustive specification. 1
The one-page structure I use
| Section | What goes in it | Where it usually goes wrong |
|---|---|---|
| Problem | Who's affected, what they're trying to do, and your evidence | Describing a solution instead |
| Goal | The change you expect, in a sentence or two | Listing features and calling them goals |
| Scope | What the first version includes | Quietly including everything "for later" |
| Non-goals | What this version deliberately leaves out | Skipping it, so scope creeps in |
| Success measures | The metric, the baseline, and the review date | Picking the metric after launch |
| Constraints | Dates, dependencies, compliance, platform limits | Hiding a real deadline |
| Open questions | What's unresolved and who owns each one | Pretending everything is settled |
If I had to keep only one section, it would be non-goals. A plain "we're not doing X in this version" has saved me more rework than pages of detail about what we were doing.
Evidence over adjectives
"Users find checkout confusing" is an opinion. "The most common checkout complaint in support last month was people not knowing whether their booking went through" gives the team something to work with.
The evidence doesn't have to be perfect. Just say where it came from, whether that's analytics, support tickets, interviews or your own hunch. Hunches are fine as long as they're labelled.
Decide the measure before the design
If you choose how to measure a feature after it ships, you'll almost always find a number that looks good. So write down beforehand which metric should move, which one shouldn't get worse, and when you'll check.
Something like: "Reduce booking-status support contacts. Guardrail: checkout completion shouldn't drop. Review four weeks after full rollout."
That one line tells engineers what the feature is protecting, and it changes how they handle edge cases.
Leave the solution partly open
If the PRD specifies every button, the people who know the technology best get shut out of the decision. I describe the outcome, the constraints, and the parts of the experience that genuinely can't change. The rest we work out with design and engineering.
User stories and acceptance criteria can sit underneath for the actual build. That's a different level of detail for a different job.
Keep a short decision log
Once work starts, update the open questions in the same document and add a small log at the bottom: what changed, when, and why. Two lines per decision is plenty.
Six weeks later, when someone asks why the feature works the way it does, the answer is one link away. For me, that's the real test of a PRD.