Bob Lee, creator of Cash App and former CTO of Square, stabbed to death

Bob Lee, chief product officer at MobileCoin, was killed in a fatal stabbing in San Francisco. At 2:35 a.m. Tuesday morning, the San Francisco Police Department responded to a report of a stabbing near the 300 block of Main Street in SoMa. He was taken to hospital but succumbed to his injuries.

Shortly after, NBC Bay Area reported that the stabbing victim was 43-year-old Bob Lee. MobileCoin confirmed the information in a statement sent to Bloomberg and ABC7 News.

Prior to joining MobileCoin, Bob Lee worked at Google during the early years of Android, focusing on core library development. He then joined Square – the payment company that later became Block – to develop the Android app. He became the company’s first CTO and also created Cash App.

Bob Lee, also known as “Crazy Bob”, was also an investor in tech startups. According to his LinkedIn profile, he has invested in SpaceX, Clubhouse, Tile, Figma, Faire, Orchid, Addressable, Nana, Ticket Fairy, Gowalla, Asha, SiPhox, Netswitch, Found and others.

Following the news, there was an outpouring of grief in the tech community. “Right. Getting calls. Heartbreaking. Bob was instrumental in Square and Cash App. STL guy,” Block CEO Jack Dorsey wrote on Nostr.

“So sad to hear of @crazybob’s untimely passing. I first met him in the summer of 2006 – he didn’t care that I was only 14 and we were talking about tech/programming. We we’ve stayed connected over the years and he was an early supporter of Figma. It’s so hard to believe he’s gone,” Dylan Field, CEO of Figma writing on Twitter.

“What a tragedy. I remember Bob’s code generating certain numbers. Bob’s code is in Java, but uses clever backtracking techniques to get the best performance out of many solutions in all sorts of languages,” said writes hintymad on Hacker News.

No arrests have been made in the case and the San Francisco Police Department has not shared any additional details.