This document summarizes the lessons learned by Hardi Meybaum, the founder of Grabcad, over several years of building the company. It outlines 19 key lessons, including not giving up after failures, celebrating small victories, having an understanding support system, talking to customers, experimenting, and the importance of building a strong team of people you enjoy working with. Major milestones are also noted, such as launching the initial product, raising funding rounds, and Terry becoming a top customer after being one of the first to use the platform.