Cloud infrastructure company Fly.io announced a $25 million Series D round co-led by Dell Technologies Capital and Intel Capital, with participation from Andreessen Horowitz, alongside a leadership change: founder Kurt Mackey is stepping down as CEO, handing the role to Scott Johnston, who previously led Docker as it narrowed from a broad enterprise platform into a focused developer-tools company. Both moves formalize a repositioning Fly.io has been signaling for months — away from general-purpose app hosting and toward what the company calls "Computers for Agents."

From stateless containers to persistent agent machines

Fly.io's pitch centers on Sprites, its infrastructure product for giving AI coding agents — the kind embedded in tools like Claude Code — a persistent, hardware-isolated Linux environment instead of a disposable, stateless container. The idea is that an agent's files, running processes, and accumulated state should survive between tasks the way a human developer's own machine does, rather than resetting each time a session ends. The company says roughly 8,000 customers are already building agent products on its infrastructure, a figure it plans to grow using the new capital and Johnston's experience scaling a developer-infrastructure business through a comparable strategic narrowing at Docker after its 2019 split into a slimmed-down developer product and a separately sold enterprise business.

A funding history that tracks the pivot

The Series D follows a $12 million Series A, a $25 million Series B led by Andreessen Horowitz, and a $70 million Series C led by EQT Ventures, tracing Fly.io's evolution from a general application-hosting platform toward infrastructure purpose-built for autonomous coding agents. Mackey is not leaving the company outright, moving instead into a different role as Johnston takes over day-to-day leadership and a board seat.

Why it matters

The round is a small but telling data point in a broader shift: as coding and computer-use agents move from demos into always-on tools, infrastructure vendors are re-architecting compute around what agents specifically need — persistent state, sandboxed isolation, and fast startup — rather than retrofitting containers designed for stateless web apps. Fly.io's bet, backed by a CEO hire chosen specifically for having steered a developer-tools company through a similar identity shift, signals that investors are treating "compute for agents" as its own distinct infrastructure category, one already being contested by rivals like E2B and Browserbase, rather than a feature bolted onto existing cloud platforms.