Sebastian's background spans both sides of deep-tech investing, having worked at Goldman Sachs and a German family office before joining Sunfish Partners, where he supports technical founders building foundational technologies and stays close to Europe's dual-use and defense ecosystem through his ties to NATO DIANA, Palladion, and Mission 2044. He also keeps a hands-on connection to startups outside investing, having built the sales network for mietshausverkaufen.de, done business development work at Sqanit, and held an operating role at healthtech startup DasLab, experience that lines up with his view that having the wrong investor is worse than having no investor at all.