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Series A Biotech companies in San Francisco

Companies applying biology, chemistry, and computation to therapeutics and tooling. Filtered to Series A-stage companies headquartered in San Francisco.

Built from a search like: Top Series A Biotech companies in San Francisco

Ranked by current headcount across Series A Biotech companies in San Francisco. Refreshed daily.

  1. 1
    Genentech· South San Francisco, California, United States
    • Series A
    • 18.1k employees
    • Founded 1976
  2. 2
    Xaira Therapeutics· South San Francisco, California, United States
    • Series A
    • 192 employees
    • Founded 2023
  3. 3
    iZumi· South San Francisco, California, United States
    • Series A
    • 92 employees
    • Founded 2007
  4. 4
    BIOMAKERS· San Francisco, California, United States
    • Series A
    • 77 employees
    • Founded 2014
  5. 5
    Addition Therapeutics· South San Francisco, California, United States
    • Series A
    • 64 employees
  6. 6
    OneSkin· San Francisco, California, United States
    • Series A
    • 57 employees
    • Founded 2016
  7. 7
    TRexBio· South San Francisco, California, United States
    • Series A
    • 56 employees
    • Founded 2018
  8. 8
    SonoThera· South San Francisco, California, United States
    • Series A
    • 49 employees
    • Founded 2021
  9. 9
    Until· San Francisco, California, United States
    • Series A
    • 46 employees
    • Founded 2024
  10. 10
    Vilya· South San Francisco, California, United States
    • Series A
    • 45 employees
    • Founded 2022
  11. 11
    Tenvie Therapeutics· South San Francisco, California, United States
    • Series A
    • 43 employees
    • Founded 2025
  12. 12
    Shinobi Therapeutics· South San Francisco, California, United States
    • Series A
    • 41 employees
    • Founded 2023
  13. 13
    Rezo Therapeutics· San Francisco, California, United States
    • Series A
    • 40 employees
    • Founded 2021
  14. 14
    Gordian Biotechnology· South San Francisco, California, United States
    • Series A
    • 39 employees
    • Founded 2018
  15. 15
    SyntheX· San Francisco, California, United States
    • Series A
    • 34 employees
    • Founded 2016
  16. 16
    Nudge· San Francisco, California, United States
    • Series A
    • 33 employees
    • Founded 2024
  17. 17
    Mission Barns· San Francisco, California, United States
    • Series A
    • 32 employees
    • Founded 2018
  18. 18
    Nura Bio· South San Francisco, California, United States
    • Series A
    • 31 employees
    • Founded 2018
  19. 19
    Switch Therapeutics· San Francisco, California, United States
    • Series A
    • 30 employees
    • Founded 2020
  20. 20
    Atomic AI· South San Francisco, California, United States
    • Series A
    • 30 employees
    • Founded 2021
  21. 21
    Prolynx· San Francisco, California, United States
    • Series A
    • 30 employees
    • Founded 2009
  22. 22
    3T Biosciences· South San Francisco, California, United States
    • Series A
    • 29 employees
    • Founded 2017
  23. 23
    CIONIC· San Francisco, California, United States
    • Series A
    • 29 employees
    • Founded 2018
  24. 24
    Deep Apple Therapeutics· San Francisco Bay Area
    • Series A
    • 29 employees
    • Founded 2022
  25. 25
    Faeth Therapeutics· San Francisco, California, United States
    • Series A
    • 28 employees
    • Founded 2019

Find engineers at Series A Biotech companies in San Francisco

Searching for “engineers at top Series A Biotech companies in San Francisco” surfaces this slice of the market. The list above ranks Biotech companies headquartered in San Francisco whose latest disclosed round is Series A, by current headcount, drawn from public LinkedIn and Crunchbase records. With 57 matching companies in our index, this is a tight read on where the Biotech talent in San Francisco is heating up.

Three filters at once narrows the field hard. The companies that survive all three — Series A, Biotech, in San Francisco — are usually the most targeted recruiting pool a hiring manager can ask for. Senior engineers, founding designers, and product leads here are about to become Biotech’s next operators and angel investors.

Refolk converts this list into a live search. Ask for “senior engineers at Series A Biotech companies in San Francisco hiring” or “founders of Series A Biotech companies in San Francisco who left in the last year” and Refolk returns a ranked shortlist with the evidence behind each match.

How this list is built

Refolk pulled Biotech companies headquartered in San Francisco whose latest disclosed funding round is Series A from public LinkedIn and Crunchbase records, ranked them by current employee count, and kept those with at least 3 employees. The list refreshes once a day.

Last refreshed: Thu, 07 May 2026 08:09:49 GMT

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