What is Claude Code?

Claude Code is now used to autonomously maintain its own codebase daily via a Slack channel running routines for dead code cleanup, experiment shipping, test writing, and abstraction unification.

“We actually have quad maintaining itself now. And the way we do this is we have a Slack channel where we just had Cloud start a bunch of different routines to maintain its own codebase.”

Meta instructed teams to stop using Codex and Claude Code on certain tasks out of concern that model outputs could contaminate its own training data, revealing an internal tension in AI-assisted development at frontier labs.

“One memo told teams to discontinue the use of Codex and Claude code on certain tasks for fear that model outputs could contaminate training data.”

Over 90% of Anthropic's own code is now written by Claude Code.

“90 plus% of our code is actually written by cloud code.”

Claude Code's multi-agent code review feature, which traverses an entire codebase simultaneously, only became production-reliable with Opus 4.5, Opus 4.6, and Sonnet 4.6.

“It was only with like Opus 45 and 46 that we and Sonnet 4.6 that we felt like okay we are now able to like run multiple code review agents simultaneously to traverse the entirety of the codebase and to synthesize a set of like real issues that an engineer needs to address before merge.”

Claude Code helped Samsung cut system-on-chip verification time from 3 months to 2 days.

“Development personnel have been able to cut down the time to complete complex tasks like system on chip verification from 3 months to 2 days.”

US software development job postings rose 15% since Claude Code launched in late February 2025, while overall job postings fell 7% in the same period. 71% of those gains came from senior roles.

“US software development job postings are up 15% since the launch of Claude Code in late February 2025, while overall job postings fell by 7% over the same period. And it's not a junior rebound. 71% of the gains came from senior roles.”

Anthropic reported that 65% of its product team code is now initiated via Claude Code from Slack rather than from the Claude app or terminal.

“Anthropic saying that 65% of its product team code was now being produced not in the Claude app or in the Claude Code terminal experience, but by initiating Claude Code from Slack.”

Owner's internal agent Owen uses Claude Code with full codebase visibility to auto-generate first-draft pull requests when bugs are reported in Slack.

“Could Owen call cloud code which has full visibility into our codebase and just immediately when a Slack message is posted from a product person, a design person, a support person reporting a bug, jump in and do the first draft PR.”

Claude Code (Anthropic) is worth watching as a leading indicator for software labor demand: job postings surged 15% in the months after its late February 2025 launch, skewed toward senior roles.

“US software development job postings are up 15% since the launch of Claude Code in late February 2025, while overall job postings fell by 7% over the same period.”

Anthropic worth watching: run rate revenue tripled in one quarter, net dollar retention above 500%, and over 90% of its own code now written by Claude Code

“Run rate revenue went from 9 billion to 30 billion in one quarter.”