Coding Agents Are Wearing Down the Code They Write -- AI Brief October 5

Good day %%first_name%%. Sourcegraph’s CEO says coding agents are wearing down the very codebases they write into, Microsoft’s annual security report says attackers got the AI head start, and a shopper agent walks into a store with nobody behind the counter. Also on the menu: a Composio engineer declaring dashboards dead, and two governors from opposite parties deciding not to wait for Washington. Let’s get into it.

Coding Agents Are Eroding Big Codebases AI Engineer

* What happened: Sourcegraph CEO Dan Adler told the AI Engineer World’s Fair that coding agents are producing a “tidal wave” of code, and the decades-old codebases that run banks, cars and airlines are starting to decay: duplicated code, drifting standards, brittle dependencies and fresh vulnerabilities. The talk went up on YouTube Sunday and doubles as a pitch for Sourcegraph’s Agentic Batch Changes, which makes one change across thousands of repositories from a single prompt.

* Why it matters: A repository is one project’s folder of code, and a big company can have tens of thousands of them. Adler’s argument is that context, not model quality, is the bottleneck: agents understand code by searching, and “you can’t grep what you can’t see.” He also says 72% of software jobs are at companies with more than 500 people, so the old, sprawling code he’s describing is where most programmers actually work.

* What everyone’s saying: Sourcegraph’s launch post, dated September 14, says customers merged nearly a thousand changesets during the beta, and quotes Mercari’s Patrick Klitzke fixing a GitHub Actions configuration vulnerability with one prompt, then finding “around 80 potential repos affected” across the company. Viewers under the video aren’t all sold: two commenters note the talk was filmed in June and question whether newer models have already overtaken it.

* My read between the lines: Agents made the sprawl, and the vendor is now selling an agent to count it. The detail I trust is the pricing: Sourcegraph charges per changeset your team actually merges, not per token, seat or attempt. A company that only gets paid for work you accept either believes its demo or has run out of other ideas.

📖 Further reading: The Boring Layer That Decides If Your AI Survives — Adler calls owning a big codebase the unglamorous, load-bearing work, and this is my post on the plumbing nobody notices until 3am.

Ninety thousand repositories is Sourcegraph’s problem. Yours is probably ninety open tabs and a report due Friday. Viktor is an AI agent that lives in Slack and connects to 3,000+ of your tools, then does the work: reports, dashboards, code and campaigns. Not a chatbot. A coworker you brief like one. New readers get $50 off their first month. Hire Viktor →

Shopper Agents Have Nobody to Haggle With Platforms

* What happened: Sangeet Paul Choudary argues in his Platforms newsletter that consumer-side agents like Meta’s Muse and Instinct can search, compare and eventually buy for you, but sellers still answer with catalogues, price lists and fixed offers. He calls the result a “lopsided agent economy” and puts it plainly: “We have agentic participants but don’t have agentic markets yet.”

* Why it matters: His travel example makes it concrete. A traveller’s agent can know she’d leave a day earlier for a nonstop and pay more if a disruption is handled flexibly, but if airlines and hotels only publish fares and room categories, none of that gets used. Give the airline an agent too, and the deal is negotiated instead of picked from a menu. Two weeks ago we covered Amazon bouncing Meta’s shopping agent at the door, and Choudary’s point is that the seller side has to show up before any of this works.

* What everyone’s saying: Hiring is the example already playing out. Choudary says Indeed paused the automatic mode of its Apply For Me agent after employer feedback, and that blaming application volume misses the point: a candidate’s agent can weigh a lower title for more scope, but a job description can’t reason back.

* My read between the lines: Read it as a shopping list for somebody. Every seller who needs an agent of their own is a new customer for whoever builds one. The part he skips is what happens when both sides send bots to haggle: the humans find out what they agreed to afterward.

📖 Further reading: A Stranger Sent Me an Invite to an AI Nobody Has Written About — Instinct is one of the consumer-side agents Choudary names, and that post is my hands-on look at what it’s like to have one working for you.

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Microsoft Says Attackers Got the AI Head Start <a target="_blank" href="https://www.microsoft.com/en-us/security/blog/2026/10/01/insights-f