3. Validate & Prioritise

Static mockups tell you if something looks right. They don't tell you if it works. So designs get built into working prototypes — clickable, real enough to break — and put in front of actual users before a single line of production code gets written. This is where assumptions either hold up or don't.

What survives goes to the top of the build list. What doesn't gets written down as tested and rejected, with the reason attached — so it doesn't quietly resurface as a new idea eighteen months later. Develop & Deliver picks up only what's earned its place.

In practice, that's a Figma or code prototype in front of five to eight real users, plus a short write-up of what changed because of it.