The shift to AI-generated code has allowed Anthropic to remain relatively lean as it approaches an initial public offering that could value the company at nearly $2 trillion. According to Lesse, the grunt work of building and monitoring code has been fully handed to AI agents. 'All of our code is written by Claude,' she said. 'Like, literally all of it.' Her team previously numbered 200 as of this summer. Anthropic has been moving toward even greater autonomy: Lesse said the company now lets agents fix tests without human interaction, and it is considering allowing agents to autonomously modify the codebase. 'As engineering leaders, we're like terrified, and we're like, let's be really careful about this, but I think the line is starting to push,' she said. The company has embraced Claude Code companywide. Earlier this year, it reported that Claude wrote more than 80% of all production code at Anthropic. A recent report from the company noted that as AI agents have taken on more work, Anthropic has hired fewer junior engineers. The company's revenue growth slowed in the third quarter of this year, raising questions about whether its high valuation can be sustained without broader adoption of its AI-first approach by other companies.
Anthropic engineer says Claude writes all code for platform team
As AI lab nears IPO, its engineers rely entirely on AI-generated code
By LineZotpaper
Published
Read Time2 min
Katelyn Lesse, head of platform engineering at Anthropic, said all code written by her 200-person team is now generated by Claude, the company's AI assistant. The team, responsible for core services and developer tools, no longer writes code by hand, instead focusing on system design and verification. Lesse made the remarks at Grafana Labs' ObservabilityCON event on Tuesday.
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Analysis
Why This Matters
- If AI can write all code for a major company's platform team, it signals a potential transformation in how software engineering is done.
- The shift could lead to greater productivity and smaller teams, but also raises questions about job prospects for junior engineers and the reliability of AI-generated code.
- Anthropic's path to IPO depends on convincing other companies to adopt similar AI-first approaches.
Background
Anthropic is an AI safety startup that develops Claude, a large language model. Claude Code is its coding-focused product. The company has been gradually integrating AI agents into its own workflows, and earlier in 2026 reported that Claude wrote over 80% of the company's production code. This latest statement from Lesse indicates complete reliance on AI for coding within her team.
Key Perspectives
[Anthropic platform engineering team]: The shift to Claude-generated code has boosted efficiency and allowed the team to focus on higher-level design and verification. They see this as a natural evolution as AI models improve. [Critics/Skeptics]: Complete reliance on AI for code generation may introduce risks such as overlooked errors or security vulnerabilities, especially if agents are allowed to make unsupervised changes. The team itself expressed caution about autonomous codebase modifications.
What to Watch
- Whether Anthropic's revenue growth can pick up again, given slowing in Q3.
- Adoption of similar AI-first coding approaches by other companies, which could be a bellwether for broader industry change.
- How Anthropic balances autonomy with oversight as it pushes toward agents making independent code changes.
Sources
- Top Anthropic engineer says Claude now writes 'literally all' her team's code · All Content from Business Insider
Checked
12 claims in this story checked against 1 source: 8 supported.
Show each claim
- SupportedClaude writes all code for Anthropic’s platform team.All Content from Business Insider: “Lesse said that among her staff, which tallied 200 as of this summer, the era of human-written code is fully over.”
- Partly supportedAnthropic’s engineers rely entirely on AI-generated code.All Content from Business Insider: “And in May, Anthropic said that Claude then wrote more than 80% of the entire company's production code.”
- SupportedLesse said, “All of our code is written by Claude” and “Like, literally all of it.”All Content from Business Insider: “"When it comes to our team and how we're actually building and maintaining our systems, all of our code is written by Claude," Lesse said. "Like, literally all of it."”
- SupportedLesse said, “As engineering leaders, we're like terrified, and we're like, let's be really careful about this, but I think the line is starting to push.”All Content from Business Insider: “"As engineering leaders, we're like terrified, and we're like, let's be really careful about this, but I think the line is starting to push," Lesse said.”
- Partly supportedLesse’s team previously numbered 200 as of this summer.All Content from Business Insider: “Lesse said that among her staff, which tallied 200 as of this summer, the era of human-written code is fully over.”
- SupportedLesse made the remarks at Grafana Labs’ ObservabilityCON event on Tuesday.All Content from Business Insider: “Lesse said at Grafana Labs ' ObservabilityCON event on Tuesday”
- SupportedThe team no longer writes code by hand and instead designs systems and verifies the results.All Content from Business Insider: “Lesse said that people on her teams are still designing systems and verifications, and then offloading the actual coding to Claude.”
- SupportedAnthropic lets agents fix tests without human interaction and is considering letting them modify the codebase autonomously.All Content from Business Insider: “Lesse said Anthropic already lets agents fix tests autonomously, with no human interaction, and it's thinking about how staff can get comfortable with agents autonomously making changes to the actual codebase”
- SupportedAnthropic’s IPO could value the company at nearly $2 trillion.All Content from Business Insider: “Anthropic nears an initial public offering at a potential $2 trillion valuation.”
- SupportedEarlier this year, Claude wrote more than 80% of all production code at Anthropic, according to the company.All Content from Business Insider: “And in May, Anthropic said that Claude then wrote more than 80% of the entire company's production code.”
- Partly supportedA company report said Anthropic hired fewer junior engineers as AI agents took on more work.All Content from Business Insider: “It released a report last week saying that as AI agents have worked more inside the company, it has hired for a smaller share of junior technical positions.”
- Partly supportedSlower third-quarter revenue growth raised questions about sustaining Anthropic’s valuation without broader adoption of its AI-first approach.All Content from Business Insider: “The company's revenue growth slowed in the third quarter of this year. Maintaining its lofty valuation may depend on selling more companies on the AI-first approach espoused by Lesse and other Anthropic leaders.”