I've started three companies in a niche industry, Voice AI for restaurants: (Kea, raised $45m), (CyborgOps, acquired by Presto (YC s10), went public citing the acquisition) and VoiceBite, acquired by Checkmate months in. All three projects continue, with Kea and Presto as leaders in phone and drive-thru respectively. Earlier, I prototype a home battery at ElectriQ. Four guys in a garage built the initial systems from scratch, and deployed them to our early customers to beat out the Powerwall.