Guy Horowitz

Guy Horowitz has spent more than two decades across startups, large corporations, and venture capital, working in mobile, internet, and enterprise technology since 1998. He holds a BA in Business Administration and Economics and an MBA from the University of Haifa, with additional studies at the Technion – Israel Institute of Technology (an entrepreneurship program, 2004–2005) and UC Irvine. Early in his career he held mobile-product leadership roles at Commtouch (NASDAQ: CTCH), product management at Followap (acquired by NeuStar), and operating positions at portfolio companies including modu Mobile and TaKaDu. He was also part of the founding team of Microsoft's Israel Development Center (ILDC), serving as Director of Product Marketing.

He spent roughly five years as an investor with Gemini Israel Funds (Gemini Venture Partners), where he was involved with companies such as PrimeSense (acquired by Apple), Adap.tv (acquired by AOL), and Outbrain. In 2012 he joined Deutsche Telekom to found and run its Israel office, was promoted to Managing Director of Deutsche Telekom Business Development & Venturing in 2014, and in July 2015 became a Partner/General Partner at Deutsche Telekom Capital Partners (DTCP), where he led investments and sat as board member or observer at companies including AppsFlyer, Dynamic Yield, SafeBreach, Morphisec, FireGlass, and Replay Technologies.

More recently Horowitz has operated as General/Managing Partner at ESH.vc and as an active angel investor, and in January 2025 he announced he was joining 33N Ventures — a pan-European venture firm focused on B2B cybersecurity and infrastructure software, founded by a team that previously built a large European cybersecurity services provider (acquired by Thales) — as a Venture Partner. He has also served as Chairman of SWAN (the Smart Water Networks Forum).

• Invests primarily at seed and Series A, writing angel-scale checks (sweet spot ~$100K) into early-stage B2B tech companies, while also working on growth-stage cybersecurity/infrastructure deals through 33N.
• Core sectors: enterprise infrastructure & applications, cybersecurity, AI, analytics, e-commerce, and transportation/mobility tech.
• Strong cybersecurity orientation — his DTCP and 33N portfolios are heavy on security (SafeBreach, Morphisec, FireGlass, PerimeterX), and he writes/speaks on themes like "Will AI security take off?"
• Values strong, opinionated founders — in a public talk titled "Some of the Best Founders are Assholes," he argues the most effective founders are often uncompromising and conviction-driven rather than easy to please.
• Backs Israeli and Israeli-founded teams building enterprise/deep-tech products, leveraging a network spanning Israel, the US, and Europe.