Cat Wu quit Anthropic. On Nov. 5, she said where she landed: OpenAI, to run product management for its Core Products team16. Wu spent two years building Claude Code, the coding tool that turned into one of Anthropic's biggest hits7. She is the third person who helped build it to announce an exit from Anthropic since Oct. 24234.
cat@_catwuSome news: I’m joining OpenAI to lead product management for Core Products!
I have a lot of respect for OpenAI for showing the world that scaling works, for bringing AI to over a billion people, and for believing great products are core to the mission.
I’m excited to work with…
Three builders, ten days
Thariq Shihipar went first. He posted on Oct. 24 that he had left Anthropic after more than a year on Claude Code2. Morris posted the same news just over eight hours later that same day3.
"My colleagues at Anthropic are the most talented, thoughtful, competent, and earnest people I have ever met. I am glad they are at the wheel and trust them deeply," Shihipar wrote2. Morris, who built Claude Code's desktop app, called leaving it "the hardest thing I've done in my career"3. Both kept their plans, and their reasons, to themselves.
What two years built
Wu's last day was Friday, Oct. 30, by her own account4. She described joining the team in a Nov. 3 goodbye post. Claude Code was "a small internal tool" then, she wrote. Two years later, she called it something bigger.
"Helping build Claude Code into an industry-defining product has been the journey of a lifetime," Wu wrote4. Under her watch, the tool changed how it worked. Early users approved every action Claude took by hand.
That changed on Aug. 7, when Anthropic published an auto-mode update7. The next change came Aug. 14, when new sessions on paid plans began running in auto mode by default. A second update followed on Oct. 22, eight days before Wu's own last day. By the time she left, the default trusted Claude's judgment to act alone, migrate whole codebases and build new products inside them4.
3 Claude Code Builders Quit Anthropic Within 10 Days
Departures Anthropic's Claude Code team announced on X, Oct. 24 to Nov. 5, 2026
Each pin is one departure announced on X; the last pin is the day Cat Wu said she had joined OpenAI.
Sources: X / cat [1]; X / Thariq [2]; X / Anthony Morris [3]; X / cat [4]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Date | Event |
|---|---|
| Oct. 24, 2026 | Shihipar quits |
| Oct. 24, 2026 | Morris quits |
| Oct. 30, 2026 | Wu's last day |
| Nov. 3, 2026 | Wu's goodbye post |
| Nov. 5, 2026 | Wu joins OpenAI |
OpenAI's side of the trade
Wu's new colleague posted eight words back. "Welcome Cat. Stoked to be building together soon," wrote Thibault Sottiaux, who works on Codex and ChatGPT at OpenAI and goes by Tibo on X5.
He sits inside the same Core Products group Wu is joining, the unit that covers OpenAI's main consumer apps16. Wu, in her own post, named Sottiaux first among the colleagues she looked forward to joining. She named the wider product team and the rest of the company after him.
OpenAI's chief executive, Sam Altman, co-founded the company in 2015. Greg Brockman holds the other top job, as president. Wu praised the destination she chose over Anthropic.
"I have a lot of respect for OpenAI for showing the world that scaling works, for bringing AI to over a billion people, and for believing great products are core to the mission," Wu wrote1. Wu's billion-person figure is her own claim. She made it in the same breath as her new job title, and it still awaits an outside count to confirm it.
The numbers Anthropic filed first
Three days before Wu's post, Anthropic filed an amended prospectus for its own stock listing8. The amended filing updates the one Anthropic submitted in October, ahead of a roadshow meant to court public investors. Its numbers had cooled since that first version. Revenue for the three months through September grew more than 1,000 percent from a year earlier, to nearly $17 billion.
Growth over that stretch slowed to 47 percent, down from 144 percent in the period before it8. Anthropic swung to a $567 million operating loss, after a $974 million operating profit the quarter before. The same filing listed $895.4 billion in compute and infrastructure commitments, the cost of the frontier models Claude Code runs on.
Anthropic's Quarterly Revenue Growth Falls to 47% From 144%
Quarter-over-quarter revenue growth, Anthropic's amended S-1, filed Nov. 2, 2026
Each column is one quarter's growth over the quarter before it; the shorter column is the third quarter, filed three days before Cat Wu said she had joined OpenAI.
Fortune's figures come from Anthropic's amended S-1, which keeps Claude Code's own revenue folded into the company-wide total.
Source: Fortune [8]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| Q2 2026 | 144% |
| Q3 2026 | 47% |
Two ways to read one departure
OpenAI pulled off a coup, on one count. It hired the product lead who steered Anthropic's fastest-growing tool for two years. The hire landed days after two colleagues quit, right as Anthropic's own growth slowed on paper18. Sottiaux's eight-word welcome, on that count, is a rival savoring a win worth savoring5.
Anthropic's own evidence, on another count, points to business as usual. Shihipar said he trusted the people "at the wheel" when he left2. Morris called walking away "the hardest thing" he had done, the language of someone who still admired the place he left3. Wu's own goodbye carried gratitude toward Anthropic, start to finish4.
Both readings survive the same facts. Three people who helped build one product left it within 10 days. Each one praised the company on the way out. A friendly exit and a costly one can sit side by side.
What to do
Watch what a departing employee does, then check it against what they say. Shihipar and Morris praised Anthropic in their goodbyes, and all three builders still left within 10 days.
Weigh Anthropic's new numbers the way an investor would before its stock starts trading. A slower growth rate showed up the same week three Claude Code builders said they were leaving. So did a return to an operating loss.
By the numbers
- Ten days: the span between Thariq Shihipar's Oct. 24 exit post and Cat Wu's Nov. 3 announcement that she was leaving too24.
- $17 billion: Anthropic's third-quarter revenue, up more than 1,000 percent from a year earlier8.
- 47 percent: the company's quarterly revenue growth rate in the third quarter, down from 144 percent in the second8.
- $567 million: the resulting operating loss for the third quarter, after a $974 million operating profit the quarter before8.
- Two years: how long Wu says she worked on Claude Code before she left4.
- More than 11,000 favorites landed on Wu's post naming OpenAI as her new employer within hours1.
What to watch
Watch whether Claude Code's weekly user growth holds steady as Anthropic heads toward its stock listing8. Who Anthropic names to replace Wu, and how loudly it names them, matters almost as much. A fourth public departure from the team, or silence about that replacement, would answer the question this piece leaves open.
Sources
- cat, "Some news: I'm joining OpenAI to lead product management for Core Products!," X, Nov. 5, 2026, https://x.com/_catwu/status/2118137612577968402
- Thariq Shihipar, "I've left Anthropic after more than a year of working on Claude Code and seeing it scale larger than I ever imagined," X, Oct. 24, 2026, https://x.com/trq212/status/2113844051938054167
- Anthony Morris, "Yesterday was my last day at Anthropic," X, Oct. 24, 2026, https://x.com/amorriscode/status/2113972174524674247
- cat, "Friday was my last day at Anthropic," X, Nov. 3, 2026, https://x.com/_catwu/status/2117731934340337676
- Thibault Sottiaux, "Welcome Cat. Stoked to be building together soon.," X, Nov. 5, 2026, https://x.com/thsottiaux/status/2118138648214585591
- Jade Orin, "Cat Wu to Lead Product Management for OpenAI's Core Products," Unite.AI, Nov. 4, 2026, https://www.unite.ai/cat-wu-to-lead-product-management-for-openais-core-products/
- Aiden Cross, "Cat Wu Steps Down as Claude Code Product Chief After Two Years," Unite.AI, Nov. 3, 2026, https://www.unite.ai/cat-wu-steps-down-as-claude-code-product-chief-after-two-years/
- Beatrice Nolan, "Anthropic's growth slowed and costs jumped in the third quarter, updated IPO filing shows," Fortune, Nov. 2, 2026, https://fortune.com/2026/11/02/anthropics-growth-slowed-and-costs-jumped-in-the-third-quarter-updated-ipo-filing-shows/
