AI infrastructure startup Modal closes $750M Series D at $15.75B valuation on October 14

AI infrastructure startup Modal announced on October 14 a $750 million Series D led by Accel with Kleiner Perkins joining, alongside existing investors Menlo Ventures, General Catalyst, Redpoint Ventures, Lux Capital, Amplify Partners and Bain Capital Ventures, at a $15.75 billion post-money valuation. The round came only five months after Modal's May Series C of $355 million at a $4.65 billion valuation, more than tripling the valuation in less than half a year. The company said annualized run-rate revenue has crossed $1 billion, more than tripling the roughly $300 million reported at the Series C, with its standalone Sandboxes product contributing around $300 million annualized, having spun up nearly 3 billion sandboxes to date and demonstrated 1 million concurrent containers in an internal test. Founded in 2021 by Erik Bernhardsson, formerly of Spotify's music recommendation system, and Akshat Bubna, Modal rebuilt its file system, container runtime, scheduler and image builder for AI workloads; its customers include DoorDash, Ramp, Linear, Cognition, Runway, Physical Intelligence, Generalist AI, 1X, Suno, Chai Discovery and Achira. The new capital will go toward multi-node training, reinforcement learning and post-training products, inference improvements and expanded VM support in Sandboxes.