Jack Dorsey’s company Block publicly announced its AI “Builderbot” would take on and complete 15% of coding work, just after it laid off 4,000 people.

Jack Dorsey's Block reveals internal AI system "Builderbot," which currently performs about 200k operations daily and merges 1,500 pull requests per week, handling approximately 15% of the company's production code changes.

It has only been four months since Block laid off 4,000 people in February this year, citing AI as the reason, reducing staff by nearly 40%.

(Tagging it will make it work.)

Block states that Builderbot's usage is so simple it hardly resembles an enterprise-grade tool. Engineers just tag @builderbot in Slack and describe their needs in a sentence, and it will automatically research, plan, and implement within the discussion thread.

It proactively pulls pending tasks from Linear and Jira, opens branches, writes code, submits PRs, and iterates based on feedback. Multiple team members can collaborate with it simultaneously in the same discussion thread, watching it work and adjusting directions alongside.

How does ### differ from a typical AI assistant? It understands the entire Block.

Block emphasizes that Builderbot is different from most AI coding assistants on the market, which usually operate within a single repository. It can understand the entire system spanning hundreds of services and billions of lines of code across Block.

A developer who was originally only responsible for Cash App can now modify other services they are unfamiliar with because Builderbot already knows how those services operate. Block positions it as a tool bridging "AI coding" and "real large-scale engineering operations."

• Performs about 200k operations daily, merges 1,500 PRs weekly
• Handles roughly 15% of Block's production code changes
• Understands code across hundreds of services and billions of lines
• Only accesses source code and system configurations, not customer data, payment info, or PII
• Built on Block's open-source AI agent framework goose

"The best way to understand Builderbot is to see it as the missing middle layer between AI coding tools and large-scale engineering operations," says Brad Axen, Head of AI at Block. "What used to take months now only takes a few days."

In February this year, Dorsey announced layoffs of about 4,000 employees, reducing the staff from over 10k to around 6,000, directly attributing this acceleration to AI. Block's stock price surged by 24% after hours.

Frequently Asked Questions

What is Block's Builderbot?

Builderbot is Block's internal AI coding collaboration system, built on the open-source framework goose. Engineers tag it in Slack, and it automatically researches, codes, and opens PRs. It currently performs about 200k operations daily, handling roughly 15% of the company's production code.

Does Builderbot access Block's customer data?

No. Block emphasizes that Builderbot only accesses source code and system configurations, not customer data, payment information, or PII. Its operation scope is strictly limited to the code layer.