Block's new AI agent already writes 15% of its code — humans now just hit merge 🤖

Block, the financial services firm led by Jack Dorsey, said Wednesday that its new AI-native engineering tool, Builderbot, now handles roughly 15% of all production code changes across the company, a figure the company framed as evidence that autonomous agents have moved beyond coding assistance into day-to-day software work. The tooling executes more than 200,000 operations per day and merges approximately 1,500 pull requests per week, according to Block. Brad Axen, head of AI capabilities at Block, described Builderbot as "the missing layer between AI coding tools and how engineering actually works at scale," adding that "what used to take months now takes days."

Builderbot operates as an orchestration layer coordinating multiple AI agents across Block's full codebase, spanning every service, API and internal convention, rather than limiting activity to a single repository. The company said the setup allows any engineer to make changes anywhere in its systems, even outside their primary product area. "An engineer working on Cash App can use it to make a change in a Square service they've never touched, because the system already knows how that service works," Block said. Axen added that an idea can now move "from backlog to live in front of millions of customers in days instead of months."

The release comes against the backdrop of Block's February decision to lay off 40% of its staff, a move Dorsey attributed to the rapid acceleration of AI inside the company. Block said it is publishing details of Builderbot because it views the shift from AI-assisted coding to AI-native engineering as "one of the most important conversations happening in technology right now." The company added that the problems it is tackling, including orchestrating AI agents across a large codebase and keeping humans focused on judgment rather than scaffolding, are not unique to Block.

Other large technology firms have reported comparable adoption. Spotify engineers have been using a background coding agent called Honk, which runs a version of Claude via Anthropic's Agent SDK, and Co-CEO Gustav Söderström said on a February earnings call that the company's best developers "have not written a single line of code since December." Google CEO Sundar Pichai said in April that roughly three-quarters of the company's new code is AI-generated, and Microsoft CEO Satya Nadella said in 2025 that AI now writes between 20% and 30% of the code powering its software. Block did not provide updated employment figures alongside Wednesday's announcement.