Cal Henderson, Angel Investor

Cal Henderson is the Co‑Founder and former CTO of Slack Technologies, where he helped grow the company from its founding in 2009 to its IPO in 2019 and eventual acquisition by Salesforce in 2021. He is recognized for building products that transform workplace communication and collaboration. Before Slack, Cal was Head of Engineering at Flickr, leading development from its startup days at Ludicorp through its acquisition by Yahoo. He also served as Director of Technology at EMAP, gaining early experience in scaling digital platforms. As an angel investor, Cal has made about 15 investments, focusing on developer tools, AI, and productivity startups. His recent portfolio includes EVE, Dedalus Labs, Pally, and Swarmia, reflecting his interest in next‑generation software and infrastructure innovation.