Building the most AI-pilled engineering team in the world | Fiona Fung (Manager of the Claude Code and Cowork Teams)
6/21/20261 hr 39 min
Fiona Fung leads the teams behind Claude Code and Cowork at Anthropic (overseeing Boris Cherny and the entire engineering and PM team). Before Anthropic, she spent 11 years at Microsoft building Visual Studio and TypeScript and then moved to Meta, where she started Facebook Marketplace (now generating over $100 billion in GMV annually), worked on Meta’s first smart glasses and AR glasses, and led infrastructure, growth, integrity, and safety teams at Instagram. She’s been an engineer for over 25 years and has a unique perspective on how the role of building software is changing.
In our in-depth conversation, we discuss:
1. What she’s learned about running a team that’s shipping 8x more code than before
2. Which roles AI will transform next
3. Specific ways her team uses AI
4. How Claude “routines” have changed how she operates as a manager
5. The context-switching problem no one has solved yet
6. The biggest unsolved problem in AI
7. What keeps her up at night
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Where to find Fiona Fung:
• LinkedIn: linkedin.com/in/fionafung
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Where to find Lenny:
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• X: https://twitter.com/lennysan
• LinkedIn: https://www.linkedin.com/in/lennyrachitsky/
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In this episode, we cover:
(00:00) Introduction to Fiona Fung
(02:31) How the engineering role has transformed over 25 years
(09:28) What an AI-pilled software team looks like in 2026
(12:26) Using Claude to manage and review team output
(14:40) The evolution of code review and verification
(16:55) Who to hire: creative builders and deep systems experts
(18:18) The shift to ambitious thinking
(19:40) The growth mindset required to thrive in AI-native teams
(25:52) Helping small businesses adopt AI tools
(31:46) How Anthropic spots latent demand and builds for it
(35:08) The next frontier: asynchronous work with AI routines
(38:06) Agency and accountability in AI-native teams
(39:40) The vibe shift from token-maxing to ROI measurement
(44:24) The “bad vs. sad” quality framework
(49:34) Why all managers start as ICs at Anthropic
(55:24) Preventing skill atrophy
(58:43) Managing context switching with 20 AI agents running
(1:00:08) How PM and data science roles are transforming
(1:03:40) The importance of dogfooding and using your own product
(1:08:36) Outstanding questions
(1:12:48) The future of engineering jobs and education
(1:17:59) What keeps Fiona up at night: team culture at scale
(1:22:53) From six-month roadmaps to JIT (just-in-time) monthly planning
(1:27:03) Lightning round
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References: https://www.lennysnewsletter.com/p/building-the-most-ai-pilled-engineering
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Production and marketing by https://penname.co/. For inquiries about sponsoring the podcast, email podcast@lennyrachitsky.com.
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Lenny may be an investor in the companies discussed.
To hear more, visit www.lennysnewsletter.com
Clips
Transcript preview
First 90 secondsLenny Rachitsky· Host0:00
Anthropic engineers on average ship eight times as much code per quarter as they did compared to 2025.
Fiona Fung· Guest0:05
Coding is no longer the bottleneck. It's lifted the ceiling of what anyone is able to do.
Lenny Rachitsky· Host0:10
Everything is now possible in theory. Now it's about how ambitious can you be.
Fiona Fung· Guest0:14
It's always something we ask ourselves, what's better than me doing it? Have a bot do it.
Lenny Rachitsky· Host0:18
The people that seem to be doing best are taking the most initiative, getting the most proactive, have the most agency.
Fiona Fung· Guest0:22
We say with high agency is also high accountability, so it's all about making sure folks have that freedom to cook. But then it's also like, okay, what's the accountability for it? What's a hypothesis of what you're trying to solve?
Lenny Rachitsky· Host0:32
I'm curious what is lost in this new world of software engineering.
Fiona Fung· Guest0:36
It can start being a lonely experience 'cause we all started just working with our agents so much. And on the Claude Code team recently, we started a pairwise programming lunch.
Lenny Rachitsky· Host0:44
Something you think about is this gap forming between people that are leaning into AI, killing it, and then people that are not, super frustrated, fighting, resisting.
Fiona Fung· Guest0:52
In terms of the frustration, I think sometimes I also see a little bit of fear. For anything that there is a fear, my advice is lean in and ask, "What can I do about it? What is within my control?"
Lenny Rachitsky· Host1:02
Today, my guest is Fiona Fung. Fiona leads the teams behind Claude Code and CoWork at Anthropic. She oversees both Boris Cherny and Kat Wu, both of whom who have been on the podcast and whose episodes are in the top 10 most listened to episodes of all time. Before Anthropic, at Microsoft, Fiona ran the teams that built TypeScript and Visual Studio. After that, she went to Facebook, where she started the Facebook Marketplace team, which she took