Product Discovery is the phase at the beginning of a piece of work where we're working out what we're going to do.

This phase is used to explore a new idea or "customer problem" we are trying to solve so we can dig into the details a little more. We don't have to reserve Product Discovery just for new products; it's something that we can use to determine how we're going to build new features for an existing product too. 

The aim is to keep the process light and gather just enough information to inform what we're going to build. Remember, we won't know exactly what our customer wants until they have something in their hands, working.

If we adopt the build, measure, learn philosophy used by the Lean Startup during the implementation phase, we can validate our ideas through working software early and often, and Product Discovery will become an incremental learning process as part of that cycle.

User Story Mapping and Impact Mapping are two techniques for fleshing out the details of what we're going to build. In this section, we'll look at how to use each technique case by case. We'll then look at ways we can prioritize and begin to create our high-level roadmap and associated Product Backlog.