Guillermo Flor
About Guillermo Flor
Guillermo Flor is an entrepreneur, angel investor and writer focused on AI. He founded the Product Market Fit and AI Market Fit newsletters. Entrepreneur.com reports that they have more than 120,000 subscribers on Substack. His Substack profile describes him as a former startup founder who now invests in venture capital and writes weekly about how startups reach product market fit, growth and fundraising.
Before investing full-time he co-founded Tueri, a Valencia-based contract management SaaS company. Crunchbase lists Daniel Almaquio and Luiz Takano as co-founders. Crunchbase also lists him as a VC investor at GoHub Ventures from January 2023 to October 2025. His LinkedIn profile lists IE Business School under education.
Entrepreneur.com says he now focuses full-time on building and investing in AI.
Entrepreneur.com says he has invested in more than 40 companies, including Replit, Gru Space and dozens of Y Combinator startups. The investment dates for those companies are not public in the sources we found. Crunchbase lists only three of his personal investments: QuiverAI, Agaton and MITO AI.
Two of his AI rounds appear on the Lounge deals desk. QuiverAI raised a $8.3M seed round in February 2026, and Crunchbase lists him among its 16 investors. Andreessen Horowitz is listed as lead investor.
Agaton raised a $9.9M (EUR 8.4M) seed round in February 2026. Agaton is a Stockholm-based company that analyzes customer conversations to produce revenue intelligence. In a LinkedIn post about the round, Flor named Inception Fund and Alstin Capital as co-leads. He also named seed + speed Ventures and Foundry Ventures as participants.
Crunchbase also lists a pre-seed investment in MITO AI. The date and amount are not shown.
The public record shows him investing at pre-seed and seed, mostly in AI companies, and often alongside institutional funds. His portfolio includes startups in the US and Europe. He has not published a check size or a fund size that we could find. On X he writes about AI market trends, such as Sequoia's argument that AI companies should sell outcomes rather than software.
- QuiverAI: AI company that raised a $8.3M seed round in February 2026, led by Andreessen Horowitz.
- Agaton: Stockholm-based revenue intelligence platform built on customer conversations. It raised a $9.9M (EUR 8.4M) seed round in February 2026.
- MITO AI: Listed on Crunchbase as a pre-seed investment. The date is not public.
- Replit: Named by Entrepreneur.com as an investment. The year is not public.
- Gru Space: Named by Entrepreneur.com as an investment. The year is not public.
Investing activity
Guillermo Flor appears in 2 AI deals tracked by the Lounge deals desk. The rounds are mostly Seed, with a median round size of $10M. The most recent are QuiverAI (Seed, $8.3M, Feb 2026) and Agaton (Seed, $9.9M (EUR 8.4M), Feb 2026).
Guillermo Flor most often invests alongside Andreessen Horowitz, Andrew Pouliot, David Vazquez and Amjad Masad, and the companies they back on Lounge are mostly in AI.
Deals
Frequently asked questions about Guillermo Flor
Who is Guillermo Flor?
He is an angel investor and writer focused on AI. He founded the Product Market Fit and AI Market Fit newsletters, and he co-founded the legal tech startup Tueri.
What AI startups has Guillermo Flor invested in?
On the Lounge deals desk he appears in the QuiverAI seed round ($8.3M, February 2026) and the Agaton seed round ($9.9M, February 2026). Crunchbase also lists MITO AI at pre-seed.
What is Guillermo Flor's check size?
He has not published a check size that we could find. Founders can ask him directly.
What stage does Guillermo Flor invest in?
His public investments are at pre-seed and seed. Entrepreneur.com says his portfolio includes dozens of Y Combinator startups.
How can founders contact Guillermo Flor?
He is on LinkedIn and X (@guilleflorvs), and he publishes at productmarketfit.tech. Founders also reach him through his newsletters.
Is Guillermo Flor an angel investor?
Yes. Guillermo Flor invests personally as an angel.
What AI companies has Guillermo Flor invested in?
Guillermo Flor's AI investments include QuiverAI and Agaton. The 2 rounds on Lounge are listed on this page with amounts, dates and co-investors.
What stage does Guillermo Flor invest at?
In the rounds tracked on Lounge, Guillermo Flor has invested at Seed, with a median round of $10M.
Who does Guillermo Flor co-invest with?
Guillermo Flor's most frequent co-investors on Lounge are Andreessen Horowitz (1 deal), Andrew Pouliot (1 deal), David Vazquez (1 deal), Amjad Masad (1 deal) and Michele Catasta (1 deal).
How can founders reach Guillermo Flor?
Founders on Lounge can see Guillermo Flor's contact details in AI Investor Contacts (paid plans), check for a warm introduction through members who worked with them under Warm Paths, and add Guillermo Flor to their Investor Pipeline to track the conversation.