How do you write a good Product Requirements Document (PRD)?

Question

Accepted Answer

A **Product Requirements Document (PRD)** explains *what* you're building, *why*, and *how you'll know it worked* — so engineering and design can build the right thing without constant clarification. A good PRD is a thinking tool and an alignment artifact, not bureaucratic paperwork.

## A solid PRD outline

```text
1. PROBLEM / CONTEXT → what problem, for whom, why now
2. GOALS & SUCCESS METRICS → what outcome, how measured
3. NON-GOALS → what this explicitly does NOT cover
4. USER STORIES / REQUIREMENTS → what it must do
5. UX → flows, wireframes, key states
6. EDGE CASES → errors, empty states, limits
7. DEPENDENCIES & RISKS → what could block or break this
8. OPEN QUESTIONS → known unknowns to resolve
```

## Lead with the why

The single most important section is the **problem and goals**. If the team understands *why* and *what success looks like*, they'll often find better solutions than the one you specified. A PRD that's only a feature spec misses this.

## Non-goals are underrated

Explicitly stating what's out of scope prevents scope creep and the "while we're at it..." trap. It's as valuable as the requirements themselves.

## Common pitfalls

```text
✗ Over-specifying the HOW → boxes in engineering's better ideas
✗ No success metric → you can't tell if it worked
✗ Writing it alone → involve eng/design early to catch issues
✗ Treating it as fixed → a PRD is a living doc
```

## Why it matters

Most rework comes from misalignment: the team built what was asked, not what was needed.

A clear PRD surfaces those gaps *before* anyone writes code.

It also forces *you* to think the problem through.

If you can't write the goal and success metric clearly, you don't understand the problem well enough to build it yet.