What Is a Product Requirements Document (PRD)? | Vantage
Product Requirements Document A Product Requirements Document (PRD) is a document that defines the purpose, features, behavior, and success metrics of a product or feature. It describes what the team will build and why — not how to build it. A PRD is the contract between product management and engineering that ensures both parties share the same understanding of what done looks like before development begins.
Why product requirements document matters
Without a PRD, each team member builds a different mental model of the feature. Engineers implement their interpretation, designers create another, and the PM imagined something else entirely. The result is rework, missed requirements, and the wrong product shipped. A strong PRD aligns these mental models before a line of code is written, saving weeks of rework downstream.
How it works
A PRD covers: the problem being solved (with evidence), the target user, non-goals (what is explicitly out of scope), functional requirements (what the system must do), non-functional requirements (performance, security, accessibility), success metrics (how you will know it worked), and open questions. It is reviewed by engineering, design, and key stakeholders before work begins. PRDs evolve as requirements are clarified — version them.
Common mistakes
Writing the PRD after development starts (defeats the purpose)
Including implementation details in the PRD (the PM owns the what, engineering owns the how)
Not specifying non-goals (scope creep fills any vacuum)
Writing a PRD and never updating it as requirements clarify
Creating a PRD in isolation without engineering and design review
Related terms
How Vantage relates
Vantage generates streaming PRDs from your problem statement and context. The AI produces structured documents covering the problem, requirements, non-goals, and success metrics. PRDs are versioned automatically, so the team always knows what the current spec says and can diff any two versions.