Doppel buys YC-backed PropRise to grow its AI engineering team
What's the deal? Doppel, an AI-powered cybersecurity company focused on social engineering defense, has acquired Y Combinator-backed PropRiseDealroom has a profile for this one. Try Dealroom →. Financial terms were not disclosed. The two PropRise co-founders, Jean-Michael Diei and Matthew Krager, will join Doppel's engineering organisation.
The key hire: Diei and Krager, both former Stripe employees, founded PropRise in 2023 to build AI software for commercial real estate, serving institutional investors and real estate investment trusts (REITs). The startup grew to a high-six-figure annual recurring revenue run rate. They now join Doppel to help develop its agentic AI security platform.
What's the endgame? Doppel's Social Engineering Defense platform combines digital risk protection, human risk management, and email security to detect impersonation, phishing, and fraud. It uses AI agents to map attacker infrastructure and automate threat disruption. A shared Threat Graph links intelligence across its products, so a threat seen in one area strengthens defences elsewhere.
Why now? "As AI transforms social engineering at breakneck speed, it's vital that we challenge assumptions, adapt quickly, and build what hasn't been built before," said Rahul Madduluri, Doppel co-founder and chief technology officer. The deal is primarily a talent and capability acquisition rather than a technology integration; Doppel described no financial terms or major product merge.
The purchase caps a year of growth. In 2026, Doppel expanded into Japan and Toronto and surpassed 300 employees. It raised a $70 million Series C in November 2025, bringing total funding to $124 million and a valuation above $600 million. Backers include Bessemer Venture Partners, Andreessen Horowitz, and CrowdStrike chief executive George Kurtz.
The signal: The deal lands amid rapid cybersecurity consolidation, with buyers racing for AI and agentic-security talent — the same day CrowdStrike announced it was acquiring Fiddler AI for $400 million and Dreadnode for $95 million. Against those strategic buys, Doppel's move is modest: a small, founder-led hire to deepen its engineering bench as attackers adopt AI to scale their campaigns.
Read more: doppel.com, citybiz.co
Image credit: Doppel
