CalypsoAI

01 / WHAT IT BUILT

What the company did

CalypsoAI was an enterprise AI security startup founded in 2018 by Neil Serebryany, with offices in New York and Dublin. Its Inference Platform secured AI applications at the inference layer through three components: agentic red-teaming that simulates malicious prompts to probe for vulnerabilities, Defend, which lets enterprises create guardrails preventing AI systems from leaking sensitive data or violating regulations, and Observe, which monitors user interactions and collects technical data on security incidents. The company raised over $40 million from investors including Paladin Capital Group, Lockheed Martin Ventures and Hakluyt Capital, serving enterprises deploying generative AI.

03 / EVENT HISTORY

Events in the structured record

1. 2018
   Founded

   Founded by Neil Serebryany to secure enterprise AI applications against attacks such as prompt injection, jailbreaks and data exfiltration.

2. 2021
   Growth and funding

   Raised more than $40 million in venture funding from Paladin Capital Group, Lockheed Martin Ventures and Hakluyt Capital, building the Inference Platform with red-teaming, Defend and Observe components; led by CEO Donnchadh Casey.

3. 2025
   Acquired by F5

   F5 announced it would acquire all outstanding shares of CalypsoAI for $180 million in cash — more than four times the startup's prior funding — to integrate its AI security technology into F5's Application Delivery and Security Platform. The deal was expected to close in F5's fourth fiscal quarter of 2025.