The Lean Startup Eric Ries 2011
Ries argues that a startup is not a small version of a big company but an experiment running under extreme uncertainty, so it should be managed like one. The core loop is build, measure, learn: ship the smallest honest version of the idea, put it in front of real customers, and read the behavior rather than the compliments. He introduces validated learning, actionable metrics over vanity numbers, and the pivot as a disciplined decision rather than a panic move. The book is at its best when it attacks premature scaling, the expensive habit of perfecting a product nobody asked for. Read it for the operating rhythm, not the jargon.