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Series B AI companies in San Francisco

Companies building AI products, foundation models, and applied ML platforms. Filtered to Series B-stage companies headquartered in San Francisco.

Built from a search like: “Top Series B AI companies in San Francisco”

Ranked by current headcount across Series B AI companies in San Francisco. Refreshed daily.

  1. 1
    Vial· San Francisco, California, United States
    • Series B
    • 165 employees
    • Founded 2020
  2. 2
    Stämm· San Francisco, California, United States
    • Series B
    • 160 employees
    • Founded 2016
  3. 3
    Kardigan· South San Francisco, California, United States
    • Series B
    • 152 employees
    • Founded 2023
  4. 4
    Frontier Medicines· South San Francisco, California, United States
    • Series B
    • 76 employees
    • Founded 2018
  5. 5
    Abdera Therapeutics· South San Francisco, California, United States
    • Series B
    • 68 employees
    • Founded 2021
  6. 6
    Cartography Biosciences· South San Francisco, California, United States
    • Series B
    • 60 employees
    • Founded 2020
  7. 7
    T-knife Therapeutics· San Francisco, California, United States
    • Series B
    • 47 employees
    • Founded 2018
  8. 8
    Epicrispr Biotechnologies· South San Francisco, California, United States
    • Series B
    • 44 employees
    • Founded 2018
  9. 9
    Marea Therapeutics· San Francisco, California, United States
    • Series B
    • 35 employees
    • Founded 2022
  10. 10
    AltruBio Inc.· San Francisco, California, United States
    • Series B
    • 29 employees
    • Founded 2020
  11. 11
    HI-Bio: A Biogen Company· South San Francisco, California, United States
    • Series B
    • 25 employees
    • Founded 2021
  12. 12
    Third Harmonic Bio· San Francisco, California, United States
    • Series B
    • 13 employees
    • Founded 2019
  13. 13
    AllStripes (now PicnicHealth)· San Francisco, California, United States
    • Series B
    • 8 employees
    • Founded 2017
  14. 14
    Miroculus· San Francisco, California, United States
    • Series B
    • 8 employees
    • Founded 2014
  15. 15
    IgGenix, Inc· South San Francisco, California, United States
    • Series B
    • 6 employees
    • Founded 2019
  16. 16
    3Scan· San Francisco, California, United States
    • Series B
    • 4 employees
    • Founded 2011

Find engineers at Series B AI companies in San Francisco

Searching for “engineers at top Series B AI companies in San Francisco” surfaces this slice of the market. The list above ranks AI companies headquartered in San Francisco whose latest disclosed round is Series B, by current headcount, drawn from public LinkedIn and Crunchbase records. With 16 matching companies in our index, this is a tight read on where the AI talent in San Francisco is heating up.

Three filters at once narrows the field hard. The companies that survive all three — Series B, AI, 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 AI’s next operators and angel investors.

Refolk converts this list into a live search. Ask for “senior engineers at Series B AI companies in San Francisco hiring” or “founders of Series B AI 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 AI companies headquartered in San Francisco whose latest disclosed funding round is Series B 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 05:57:39 GMT

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