Block (Square, Cash App) rolled out BuilderBot โ an AI agent that autonomously writes code, opens pull requests, and monitors CI. Already responsible for 15% of all production code changes. 1,500 PRs merged weekly. 200,000 operations daily.
How it works: engineer tags @builderbot in Slack with a task. The agent researches, writes code across the entire codebase, creates branches, opens PRs, and iterates. Tasks that took months now take days.
Why this matters:
1,500 PRs merged weekly. 200,000 operations daily
Built on Goose (open-source, Linux Foundation) + MCP (co-developed with Anthropic)
Engineer on Cash App can modify Square services they’ve never touched โ agent knows the full codebase
Harness Theory validated: the human frames (Slack message). The agent ships (research โ code โ PR โ CI โ iterate).
Gennaro Cuofano is a CRO and tech executive who has worked in AI since late 2015, starting with bringing NLP, natural-language generation, voice and chatbot products to the marketing industry. His background is in law and finance: he holds a Master's degree in Law and an International MBA with an emphasis on corporate finance (LUISS Business School and the University of San Diego, 2012), and worked as a financial analyst at a real-estate investment firm in San Diego and as an assistant controller. His work focuses on business model strategy, business engineering and, more broadly, structural analysis: how companies make money, read from their own filings. He created FourWeekMBA and leads research there and at The Business Engineer, his newsletter on AI and business strategy, with over 95,000 subscribers and more than 1,000 published analyses. His writing has also appeared on Entrepreneur, HackerNoon and Search Engine People. Find him on LinkedIn and Substack. See how we source.
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