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Series B Cybersecurity companies in San Francisco

Companies defending or attacking software, networks, and cloud infrastructure. Filtered to Series B-stage companies headquartered in San Francisco.

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

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

  1. 1
    Cobalt· San Francisco, California, United States
    • Series B
    • 534 employees
    • Founded 2013
  2. 2
    Upwind Security· San Francisco, California, United States
    • Series B
    • 391 employees
    • Founded 2022
  3. 3
    Panther· San Francisco, California, United States
    • Series B
    • 293 employees
    • Founded 2018
  4. 4
    Riot· San Francisco, California, United States
    • Series B
    • 220 employees
    • Founded 2020
  5. 5
    Socket· San Francisco, California, United States
    • Series B
    • 85 employees
    • Founded 2020
  6. 6
    Opal Security· San Francisco, California, United States
    • Series B
    • 61 employees
    • Founded 2020
  7. 7
    Symmetry Systems· San Francisco, California, United States
    • Series B
    • 42 employees
    • Founded 2019
  8. 8
    depthfirst· San Francisco, California, United States
    • Series B
    • 30 employees
    • Founded 2024
  9. 9
    Cloudflare Area 1 Security· San Francisco, California, United States
    • Series B
    • 24 employees
    • Founded 2013
  10. 10
    BehavioSec· San Francisco, California, United States
    • Series B
    • 17 employees
    • Founded 2008
  11. 11
    Preempt, A CrowdStrike Company· San Francisco, California, United States
    • Series B
    • 9 employees
    • Founded 2014
  12. 12
    Appthority acquired by Symantec ($SYMC)· San Francisco, California, United States
    • Series B
    • 3 employees
    • Founded 2011

Find engineers at Series B Cybersecurity companies in San Francisco

Searching for “engineers at top Series B Cybersecurity companies in San Francisco” surfaces this slice of the market. The list above ranks Cybersecurity companies headquartered in San Francisco whose latest disclosed round is Series B, by current headcount, drawn from public LinkedIn and Crunchbase records. With 12 matching companies in our index, this is a tight read on where the Cybersecurity talent in San Francisco is heating up.

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

Refolk converts this list into a live search. Ask for “senior engineers at Series B Cybersecurity companies in San Francisco hiring” or “founders of Series B Cybersecurity 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 Cybersecurity 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 07:56:44 GMT

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