From 13% to 89% in Five Months: Inside Devin's Acceleration
The single most consequential number in the Series D announcement is not the $1 billion check or the $26 billion sticker — it is 89%. According to Cognition's own Series D post, Devin now writes 89% of the code committed by Cognition's engineers, up from roughly 13% at the end of 2025 [1]. That is a 6.8x jump in five months, and it is the metric the round is actually priced on. The narrative investors are buying is not 'Devin is a better autocomplete.' It is 'Devin is improving the company that builds Devin,' a recursive loop that, if it holds, compresses the engineering cost curve below anything a copilot-style tool can match.
The mechanism behind the jump is the Windsurf integration and the SWE-1.6 model release. Cognition acquired the remaining Windsurf team and IDE in July 2025 after Google reverse-acquihired Windsurf's leadership [2], which gave Devin a first-party enterprise developer environment and a routing layer that can swap between Anthropic, OpenAI, and Cognition's own SWE-1.6 — now the most-used model inside Windsurf according to Cognition's own disclosure [1]. That multi-model stack is what lets Devin run long-horizon tasks at scale without paying foundation-model rents on every token. AI2Work captured the framing bluntly: 'The company is, quite literally, building itself — and investors are betting $1 billion that this self-reinforcing loop is the future of software development' [3].
The caveat that does not show up in the blog post but does show up in the analyst read is that humans still review every Devin pull request [3]. So '89% of commits' is closer to '89% of commits drafted by an agent and approved by a human' than to fully autonomous shipping. That distinction matters because it sets the upper bound on how much of the loop is real productivity vs. how much is rebranding what used to be junior engineering work. For now, the investor consensus is that the trajectory itself — 13% to 89% in two quarters — is the signal, and that the review burden will be automated next.


