Lean Startup is a methodology for product development under uncertainty. Instead of writing a detailed business plan and then executing it, teams work in rapid cycles: formulate a hypothesis, build a Minimum Viable Product, measure the result, learn. The core insight is that with new products and business models, the greatest risk is not execution but the question of whether anyone wants the product at all.
A typical Lean Startup process begins with identifying the riskiest assumption. A team planning a platform for freelance translators does not test the technology first but whether enough clients are willing to book through a platform. A simple landing page with a contact form suffices for this. Only once the fundamental assumption is confirmed does further development proceed. This way, resources are deployed where they generate the greatest learning effect — not where they are most enjoyable to spend.
The methodology was described in 2011 by Eric Ries in The Lean Startup and has since transformed product development in startups and increasingly in corporations as well. It works wherever the future is not plannable and traditional project planning reaches its limits.