Investor profile
Frank Willemsen
Syndicate / Angel group & President, Board member at Sand Hill Angels
Frank Willemsen is a President, Board member at Sand Hill Angels, whose known portfolio counts 11 companies.
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Investment focus
Contacts
Affiliated funds' portfolios
President, Board member at Sand Hill Angels, whose known portfolio counts 11 companies
- Ratio
- ImmuneBridge
- Lōvu Health
- Lincode
- Logomix
- Speechlab
- TrueMeter
- VIAN Therapeutics
- Lovu Health
- RevelAi Health
- Clipp
Investor Profile
Frank Willemsen is listed against sectors AI, Climate, Commerce and FinTech, and focus areas AI Infrastructure, Biotech, Data and Diagnostics in the database.
Sand Hill Angels appears in Pre-Seed, Seed and Series A rounds across its known deals.
The firm portfolio and the focus above give founders context on whether Frank Willemsen matches their raise.
Colleagues at Sand Hill Angels
Showing 20 of 37
Amos Ben-Meir
Investor & Board Director
San Francisco, United States
Steve Bennet
Board Director, Membership Chair, Investor
Palo Alto, United States
John Hall
Angel Investor
Naples, United States
Srini Srinivasan
Member and Investor
San Jose, United States
Alex Ikriannikov
Investor member
San Jose, United States
Atika Sanchetee
Board of Directors, Angel Investor
San Francisco, United States
Harper Cheng
Investor
San Francisco, United States
Sarosh Kumana
Board Advisor
Incline Village, United States
Len Lehmann
Angel investor and general manager of Portola Vineyards
Portola Valley, United States
Nobu Morita
Angel Investor
Palo Alto, United States
Wei Liu
Member, Angel Investor
San Francisco, United States
Kumar Mettu
Investor
San Ramon, United States
Marco Poli
Investor
São Paulo, Brazil
Mark Mitchell
Senior Finance Executive
High Range, Australia
Aaron Feng
Angel Investor
Fremont, United States
Alan Fisher
Investor
Boca Raton, United States
Tao Xie
Angel Investor
New York, United States
Abbas Tehrani
Angel Investor
Los Gatos, United States
Edison Ren
Angel Investors
San Francisco, United States
Anat Lev Ari
Investor
Sunnyvale, United States
Frequently asked questions
Who is Frank Willemsen?
Frank Willemsen is a syndicate member based in Los Altos, California, United States, listed as President, Board member at Sand Hill Angels. The known portfolio of that firm counts 11 companies. That portfolio belongs to the firm, not to Frank Willemsen personally.
What does Frank Willemsen invest in?
Listed sectors include AI, Climate, Commerce and FinTech; listed focus areas include AI Infrastructure, Biotech, Data and Diagnostics. Those tags come from the portfolios of the firms this profile is attached to, so they read as a record of what has been backed rather than a stated preference for what comes next.
What stage does Frank Willemsen invest at?
Sand Hill Angels appears in Pre-Seed, Seed and Series A rounds across its known deals, and Frank Willemsen is listed there as President, Board member. Stage is the strongest single filter when you build a target list: an investor with no record at your stage rarely starts with you.
Which firm is Frank Willemsen listed at?
Frank Willemsen is listed as President, Board member at Sand Hill Angels. 37 other people in the database share a firm with Frank Willemsen.
How do I contact Frank Willemsen?
A LinkedIn page is on file for Frank Willemsen. It is readable inside RaiseHunt after you create an account. The database holds no email address and no phone number for this profile.
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Data: RaiseHunt investor dataset · Snapshot 5 September 2026 · How this data is built · Report a correction or request removal