On Wednesday, Jelani Nelson, a professor of theoretical computer science and chair of UC Berkeley's electrical engineering and computer science division, announced he was taking a leave of absence to join Anthropic as a Member of Technical Staff. Nelson's arrival closes a cluster of four high-profile researchers who have joined the lab in six weeks, including Andrej Karpathy, who joined in May, and Nobel laureate John Jumper, who announced his departure from Google DeepMind on June 19. Nelson brings theoretical bedrock of computational efficiency, as his research spans streaming algorithms, dimensionality reduction, and randomized algorithms, focusing on proving the minimum resources any algorithm solving a given problem must use. He completed his undergraduate, master's, and doctoral degrees at MIT, earning his PhD in 2011, joined Harvard's computer science faculty in 2013, moved to Berkeley in 2019, and in fall 2024 took over as chair of Berkeley's EECS computer science division.