To apply lean startup principles to technological innovation, you need to follow three steps: build, measure, and learn. In each step, you use different tools and techniques to validate your assumptions and hypotheses, and make data-driven decisions. For the build step, create a MVP that represents your core value proposition and riskiest assumption. Make sure it's simple and fast while not compromising on quality or functionality. When measuring, define and collect metrics that indicate how well your MVP is performing and how much value it is delivering to customers. Use quantitative methods like analytics, surveys, or experiments, or qualitative methods such as interviews, observations, or user testing. When learning from your successes and failures, analyze the data collected from your MVP and customers to draw insights and conclusions. Use tools like the lean canvas, the value proposition canvas, or the business model canvas to document and communicate your findings and assumptions. Then decide whether to persevere, pivot, or stop your innovation project.