William Callahan is an operator angel based in San Francisco, California, United States. The known portfolio counts 4 companies: Levels, SailPlan, Lessly.io and Specialty EMR Data Team.
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Investment focus
- Sector
- HealthcareSaaS
- Focus
- Digital HealthHealthcare Data InfrastructureWellness Platforms
Contacts
William Callahan portfolio companies (4)
- Levels
- SailPlan
- Lessly.io
- Specialty EMR Data Team
Investor Profile
The listing covers sectors Healthcare and SaaS, and focus areas Digital Health, Healthcare Data Infrastructure and Wellness Platforms. Startups operating in these areas may find William Callahan relevant.
Stage-wise, the known deals cluster around Growth, Seed and Series A rounds.
Reviewing the investment history helps decide whether there is a realistic fit before reaching out.
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Frequently asked questions
Who is William Callahan?
William Callahan is an operator angel based in San Francisco, California, United States with 4 known investments on file, among them Levels, SailPlan and Lessly.io. The sections above list the sectors and stages attached to that record.
What does William Callahan invest in?
Listed sectors include Healthcare and SaaS; listed focus areas include Digital Health, Healthcare Data Infrastructure and Wellness Platforms. Those tags come from the companies attached to this profile, so they read as a record of what has been backed rather than a stated preference for what comes next.
What stage does William Callahan invest at?
The known deals of William Callahan include Growth, Seed and Series A rounds. Stage is the strongest single filter when you build a target list: an investor with no record at your stage rarely starts with you.
How do I contact William Callahan?
An email address, a phone number and a LinkedIn page are on file for William Callahan. The address stays masked on this page and is readable inside RaiseHunt after you create an account.
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Data: RaiseHunt investor dataset · Snapshot 5 September 2026 · How this data is built · Report a correction or request removal