Product Requirements Document

Before a company builds a new app or feature, someone writes down what the outcome should be. That is exactly what a Product Requirements Document is, usually abbreviated as PRD. It states which problem the product solves, which user group it is intended for, and how one can later tell whether it works. It is not a blueprint for programmers, but a description of the goal. You can think of it like the assignment for a class presentation: the topic and the requirements are fixed, but how you fulfill them remains open. A PRD is usually written by someone whose role at the company is product management.

A document against talking past each other

Rarely does only two people work on a product. There are developers, designers, people from sales, and often the legal department as well. Each of these groups has its own idea of what is being built. Without a shared document, misunderstandings arise that only come to light months later.

A PRD forces a decision before money is spent. Changes to a text document cost an hour. Changes to finished code cost weeks. That is why many companies follow the rule of thumb that thinking things through up front is cheaper than fixing them afterward.

Equally important is what a PRD excludes. A good section is called “Out of Scope” and lists what will explicitly not be built. Without this boundary, a project keeps growing, an effect known as scope creep: the undertaking swells through a steady stream of small additional wishes until no deadline can be met anymore.

What actually goes into a PRD

A typical PRD begins with the problem and the goal. Next come the user groups, often in the form of short example personas. The main part consists of user stories, meaning sentences following the pattern: “As a user, I want to reset my password so that I can regain access.” Each of these requirements is worded so that one can verify whether it has been fulfilled.

On top of that come success metrics. Instead of “the search should get better,” it says something like: “80 percent of search queries return a result within 300 milliseconds.” Such figures turn a wish into a verifiable statement. Sketches of the user interface and open questions frequently round out the document.

A common misconception is that a PRD is finished once it’s written. In practice, it is continuously revised as new insights emerge. It should be distinguished from the technical design document, which the developers write themselves. The PRD says what is being built, the design document says how.

PRDs at tech companies and in AI tools

Practically every larger software company works with PRDs, from Google to SAP to small startups. When business news reports that a corporation has “scrapped” a feature, there is often a PRD behind it that was never approved. Job interviews in product management, too, frequently revolve around such documents.

For a few years now, PRDs have also been created with AI. Language models like ChatGPT deliver a first draft on request, which humans then correct. Some development tools go further and generate initial pieces of code directly from a PRD. The benefit remains limited if the requirements are unclear: a vague document leads to a vague result, regardless of whether a human or a machine implements it.