Guillermo Flor
Guillermo is a Spanish angel investor, writer and Entrepreneur magazine columnist focused on AI startups. He started as a corporate/M&A lawyer — PwC (2017–18), then Garrigues (2018–19), advising PE funds on $30M+ M&A and LBO deals — before co-founding Tueri, a B2B SaaS contract-management startup, as CEO (2020–22). He raised six figures in VC, failed to reach product-market fit, and shut it down: the origin of his PMF obsession.
After an MBA at IE Business School he joined GoHub Ventures, a €90M European seed/Series A fund, as a VC investor (2023–25), where he started writing what became Product Market Fit. Today his newsletters reach 120,000+ subscribers, he co-hosts the Compound podcast with Rubén, teaches venture capital as an associate professor at IE University, and invests full-time — 40+ angel investments and counting.
His newsletters reach 120,000+ founders and investors, with 1M+ monthly reads
270K+ LinkedIn followers — #2 VC investor on LinkedIn Spain (Favikon, 2026)
40+ angel investments — 25+ in 2025 alone, mostly alongside tier-1 VCs
Product Market Fit is a Substack top-10 tech bestseller, read in 182+ countries
Columnist at Entrepreneur, associate professor of VC at IE University, guest writer for a16z Speedrun
