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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.

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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 monthly.

  1. 1
    Cobalt· San Francisco, California, United States

    Cobalt is a leader in continuous offensive security. Only Cobalt brings together human expertise, a context aware platform, AI-driven orchestration, and the industry's largest dataset of real-world pentest results. Thousands of customers rely on Cobalt and its global network of 500+ security experts to continuously identify, prioritize, and remediate risk.

    • Series B
    • 597 employees
    • Founded 2013
  2. 2
    Riot· San Francisco, California, United States

    In today's world, most successful cyberattacks start with a human failure. We're making the platform that makes it easy to prepare your employees for cyberattacks, in a way they love.

    • Series B
    • 256 employees
    • Founded 2020
  3. 3
    Panther· San Francisco, California, United States

    Panther is the AI SOC Platform that scales security expertise by embedding AI agents across your security operations with native access to your data lake, detection logic, and organizational knowledge. Unlike bolt-on tools, Panther's closed-loop architecture turns every alert into compounding intelligence that makes the system smarter over time.

    • Series B
    • 248 employees
    • Founded 2018
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  5. 4
    Relyance AI· San Francisco, California, United States

    Maps all paths AI and identities take to sensitive data. Enforce runtime guardrails. Cut the access and actions that shouldn’t exist.

    • Series B
    • 66 employees
    • Founded 2020
  6. 5
    depthfirst· San Francisco, California, United States

    Backed by Meritech and Accel, depthfirst is an applied AI security lab built to secure the world's software. Software runs civilization, powering everything from social apps to retail, hospitals, banks, power grids, defense systems. AI makes it easier than ever to find and exploit software vulnerabilities at scale. depthfirst acts as the definitive defensive layer for enterprise applications by deeply understanding code, infrastructure, and underlying business logic.Our elite founding team bridges the gap between infrastructure and frontier AI research, drawing from Databricks, Faire, and Google DeepMind to build autonomous, custom models that detect and fix complex vulnerabilities. Security has never been more critical, and we’re redefining what it means to protect software for the next generation.

    • Series B
    • 66 employees
    • Founded 2024

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 Refolk’s 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 monthly.

Last refreshed: Tue, 15 Sep 2026 18:44:43 GMT

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How is this ranking built?

The list draws on the public company graph - headcount and growth signals, funding history, and recency. The criteria chips at the top show exactly which filters produced it, and the methodology section explains the ranking.

How fresh is the data?

The underlying index updates continuously and this ranking is rebuilt monthly. Last refreshed: Tue, 15 Sep 2026 18:44:43 GMT. For a list built against the index as it stands today, sign up and run the search live.

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