The principles behind lean startup methodologies focus on minimizing waste and maximizing value through iterative development. Key concepts include the Build-Measure-Learn cycle, where early-stage ideas are rapidly prototyped and validated. Startups aim to gather customer feedback to shape product development, allowing for pivoting if necessary. This approach encourages validated learning to ensure that products meet actual market needs rather than assumptions. By fostering a sustainable growth model, lean startups can adapt quickly to change and establish a strong market fit.