Investors & Partners at Joule Ventures

Brian Rosenzweig

Co-Founder & Partner, Joule Ventures

Brian is a bi-cultural operator-investor who was born and educated in the U.S. but spent most of his career embedded in Israel's innovation ecosystem, giving him hands-on experience helping Israeli founding teams with product-market fit and North American go-to-market strategies. Before co-founding Joule, he served as Director of Marketing at New York-based venture fund 21Ventures while living in Israel, where he designed and executed market entry strategies for 45+ portfolio companies—an unusual role where he functioned as a go-to-market strategist for an entire fund's portfolio rather than a single startup.

Daniel Frankenstein

Co-Founder & Partner, Joule Ventures

Daniel Frankenstein is Co-Founder and Partner at Joule Ventures, a venture capital firm focused on identifying and scaling transformative technology companies. With deep expertise across enterprise software, cybersecurity, artificial intelligence, financial technology, and SaaS, Daniel brings a strategic investment perspective to emerging companies addressing critical market needs. As a co-founder of Joule Ventures, he plays a central role in the firm's investment strategy, portfolio management, and value creation initiatives. Daniel's investment thesis emphasizes backing founders building mission-critical solutions that drive operational efficiency and competitive advantage across enterprise sectors. His career reflects a commitment to supporting entrepreneurs at the intersection of technology innovation and business fundamentals.