Refolk

Top Series A AI companies

Companies building AI products, foundation models, and applied ML platforms. Filtered to companies whose latest disclosed round is Series A.

Built from a search like: Top Series A AI companies

Ranked by current headcount across Series A AI companies. Refreshed daily.

  1. 1
    Genentech· South San Francisco, California, United States
    • Series A
    • 18.1k employees
    • Founded 1976
  2. 2
    Google DeepMind· London, England, United Kingdom
    • Series A
    • 8.3k employees
    • Founded 2010
  3. 3
    Esco· Singapore, Singapore
    • Series A
    • 1.3k employees
    • Founded 1978
  4. 4
    ISQ· Oeiras, Lisbon, Portugal
    • Series A
    • 1.2k employees
    • Founded 1965
  5. 5
    MedImmune· Gaithersburg, Maryland, United States
    • Series A
    • 906 employees
    • Founded 1987
  6. 6
    Rentschler Biopharma· Laupheim, Baden-Württemberg, Germany
    • Series A
    • 898 employees
    • Founded 1927
  7. 7
    Altos Labs
    • Series A
    • 576 employees
    • Founded 2021
  8. 8
    BlueRock Therapeutics· Cambridge, Massachusetts, United States
    • Series A
    • 463 employees
    • Founded 2016
  9. 9
    LLLL· Shawnee, Kansas, United States
    • Series A
    • 459 employees
    • Founded 2010
  10. 10
    Meihua Holdings Group Co., Ltd.· China
    • Series A
    • 441 employees
    • Founded 2002
  11. 11
    Isomorphic Labs· London, England, United Kingdom
    • Series A
    • 348 employees
    • Founded 2021
  12. 12
    GENEWIZ from Azenta Life Sciences· South Plainfield, New Jersey, United States
    • Series A
    • 307 employees
    • Founded 2021
  13. 13
    Stylus· London, England, United Kingdom
    • Series A
    • 256 employees
    • Founded 2010
  14. 14
    Watchmaker Genomics· Boulder, Colorado, United States
    • Series A
    • 236 employees
    • Founded 2019
  15. 15
    Health in Code Group· Valencia, Valencian Community, Spain
    • Series A
    • 227 employees
    • Founded 2001
  16. 16
    Vital Bio· Oakville, Ontario, Canada
    • Series A
    • 224 employees
    • Founded 2019
  17. 17
    Andes· Alameda, California, United States
    • Series A
    • 219 employees
    • Founded 2018
  18. 18
    ADAPT· Millers Point, New South Wales, Australia
    • Series A
    • 202 employees
    • Founded 2011
  19. 19
    Xaira Therapeutics· South San Francisco, California, United States
    • Series A
    • 192 employees
    • Founded 2023
  20. 20
    Partner Therapeutics· Lexington, Massachusetts, United States
    • Series A
    • 187 employees
    • Founded 2017
  21. 21
    1Cell.Ai Inc.· Mumbai, Maharashtra, India
    • Series A
    • 184 employees
    • Founded 2021
  22. 22
    Refeyn· Oxford, England, United Kingdom
    • Series A
    • 177 employees
    • Founded 2018
  23. 23
    Treeline· Watertown, Massachusetts, United States
    • Series A
    • 162 employees
    • Founded 2021
  24. 24
    Hawthorne Health, Inc.· Walnut Creek, California, United States
    • Series A
    • 159 employees
    • Founded 2015
  25. 25
    NANO· Eindhoven, North Brabant, Netherlands
    • Series A
    • 153 employees
    • Founded 2019

Find engineers and founders at Series A AI companies

Series A AI companies are some of the most active hirers in the market. The list above ranks the largest AI companies whose latest disclosed round is Series A, by current headcount, drawn from public LinkedIn and Crunchbase records. Across 853matching companies, you’ll find senior engineers, founding designers, and operators worth tracking.

Companies at this stage in AI share a profile: a working product, fresh capital, and a hiring plan that wants senior people yesterday. Looking at headcount, last round, and HQ side by side gives you a quick read on where AI talent is concentrating right now.

Refolk converts this list into a search. Ask for Series A AI founders hiring senior engineers” or “design leads at Series A AI companies” and Refolk returns a fresh ranked shortlist with the sources behind each match.

How this list is built

Refolk pulled AI companies 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 5 employees. The list refreshes once a day.

Last refreshed: Thu, 07 May 2026 07:56:14 GMT

Need an even more specific search?

Refolk runs natural-language searches across LinkedIn, GitHub, and the open web. Try one of these:

Related lists

See all company lists.

Or zoom out

Slice this list a different way