Doppel Acquires YC-Backed PropRise for AI Defense
By @sharedot · · 6 pages
- Startups
- M A
- Cybersecurity
- Y Combinator
Cybersecurity startup Doppel has acquired YC-backed PropRise, adding its Stripe founder duo to an expanding agentic AI engineering push.
Doppel buys PropRise to power agentic AI defense
Cybersecurity company Doppel has acquired PropRise, a Y Combinator-backed startup founded in 2023 by former Stripe employees Jean-Michael Diei and Matthew Krager, according to Pulse 2.0.
The deal moves both founders into Doppel's engineering organization as the company expands its agentic AI capabilities. PropRise had grown to a high-six-figure annual recurring revenue level before the acquisition, per Pulse 2.0, an unusually mature position for a startup less than three years old.
Doppel develops AI-powered defenses against social engineering, combining digital risk protection, human risk management and email security on a shared intelligence architecture in which its Threat Graph lets signals from one product inform defenses across the platform.
Why a founder acqui-hire at this price point matters
Doppel co-founder and CTO Rahul Madduluri framed the hire as a bet on builder mentality, saying his team seeks founders who can 'build what hasn't been built before' as AI transforms social engineering at breakneck speed.
Diei, PropRise's CEO, said his three years at the frontier of agentic AI position the team for a new generation of agentic defense solutions.
The move also fits a bigger 2026 for Doppel: international operations in Japan and Toronto, new platform capabilities, more than 300 employees, and backing from Bessemer Venture Partners and Andreessen Horowitz, with CrowdStrike CEO George Kurtz among strategic investors, according to Pulse 2.0.
The stakes: AI is arming both attackers and defenders
Doppel's platform is built for a threat landscape where impersonation, phishing and fraud scale with the same AI tools defenders use. Its agentic AI is designed to identify relationships among threats across digital channels, while AI agents look for missed detections and emerging attack methods.
The company's Human Risk Management technology turns real-world attack patterns into employee simulations and training.
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