How I’d prep for Anthropic’s Staff+ Software Engineer, Consumer role

Good news, bad news

The good news: Anthropic has moved away from most LeetCode-style interviews. Reports describe practical coding instead, where you build a small system in stages, and some candidates in 2026 describe a round where you code with Claude Code. Formats vary by role and by month, so ask your recruiter what yours looks like.

The bad news: Anthropic is one of the hardest companies in tech to get into. This is a Staff+ role on a founding team, so the resume has to carry real weight before any of this prep matters. If yours does, here’s how I’d spend the next 30 days.

What this team does

From the posting: a small zero-to-one team building brand new consumer AI products on frontier Claude models. You’d be a founding engineer. Nobody hands you a spec. You come up with the bet, cut it down to the leanest real first version, ship it, and keep going when most bets don’t work the first time.

System design questions

• Design a one-to-one chat system. How do you handle presence, message ordering and a user on two devices?
• Design the streaming layer for a chat app with millions of users talking to an LLM. What happens when a connection drops mid-response?
• Design conversation history that syncs across web and mobile.
• Your chat app feels slow. Walk through where the time goes, from the click to the last token.

Concepts they’ll probe

• Server-sent events vs WebSockets vs long polling: when would you pick each?
• Backpressure: what do you do when the client reads slower than the model writes?
• Resuming a stream after a dropped connection without duplicating text.
• Keeping React fast while text streams in: batching updates, avoiding re-renders.
• Cutting bundle size and time to first token on a consumer web app.