A lean MVP is an MVP that’s ruthless about scope. The Eric-Ries flavor: build the smallest thing that lets you measure what you want to learn, then iterate. The 5-day MVP is the most aggressive practical interpretation of the lean MVP frame.
Why it matters
Most "MVPs" in the wild are not lean. They have a six-week build, a four-week design phase, and a three-month roadmap before the first customer touches them. A lean MVP collapses all of that into a week, on the bet that customer signal beats internal planning.
Common mistakes
- Confusing lean with sloppy. Lean means "no extra features," not "no infrastructure." Auth, payments, and a real database are non-negotiable.
- Skipping measurement. A lean MVP without analytics teaches you nothing. PostHog or Plausible from day one.