Left Anthropic in March after 8 months as a mid-level SWE. Writing this because I couldn't find anything honest when I was researching them, just breathless mission-speak and some very suspicious glassdoor reviews.
The WLB situation is genuinely complicated, and I don't think anyone can give you a clean answer because it varies a lot by team. Here's what I observed.
The mission thing is real, and that's actually the problem. A lot of people there genuinely believe they're working on something that matters more than anything else. That creates a culture where working past midnight doesn't feel like exploitation, it feels like participation. I watched a few colleagues slide into 70-hour weeks not because anyone asked them to, but because the work felt urgent. If that resonates with you, Anthropic might be energizing. If it worries you, it should.
Formal expectations are reasonable. Nobody told me I had to work weekends. PTO is unlimited on paper. The 2026 SF office setup is nice, perks are solid. On paper it looks like a healthy tech company.
In practice the pressure is ambient. Meetings run long. The pace of shipping is fast. Roadmaps change weekly because the underlying research changes weekly. If you're a person who needs predictability to protect your personal time, that friction adds up. I'm good at disconnecting and I still found it hard some weeks.
Team matters enormously. The infra and platform orgs seemed calmer than the teams closer to model work. Applied research and the product orgs in between felt somewhere in the middle. I can only really speak to my corner.
Culture notes: Very SF startup energy, not big-tech energy. More free-form opinions in meetings than most places I've worked. Smart people who aren't afraid to push back, which is mostly good but means you need thick skin. Internal debate about safety tradeoffs is frequent and sometimes gets heated.
People who loved it were either deeply mission-aligned or just genuinely interested in the problems. People who burned out usually came in expecting FAANG-style structure and found that Anthropic is still figuring things out as it scales. The company went from like 100 to 800 people in two years. That shows.
I don't regret going. I do regret not asking harder questions about team culture in my interviews. If you're considering it, I'd suggest getting very specific with your interviewer about what the last 3 weeks actually looked like for them, not in general.