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Frontend interview guide

Anthropic

Claude, the Claude app, the Claude Code CLI, the Console. An AI-safety-first culture with a growing frontend footprint and a visibly thoughtful hiring bar.

Frontend engineers interviewing at Anthropic — React/TypeScript across chat, developer tools, and the Console. Loops are smaller than FAANG, and the behavioural signal is heavy.

Last reviewed 2026-10-04

What they emphasise

  • Thoughtfulness — in code, in writing, and in how you reason about trade-offs. Clever is secondary to considered.
  • Streaming/LLM UX — how to build and reason about token-by-token UIs, cancellation, retries, tool use.
  • Writing culture — docs, specs, long-form PRs are the medium most work moves through.
  • Safety- and values-aligned thinking — you'll be asked how you weigh risks, not just how you build features.

The loop, round by round

6 rounds. Durations and formats are typical, not guaranteed — confirm the loop shape with your recruiter in the screen.

  1. Round 1

    Recruiter screen

    ~30 minCall

    What it covers

    • Resume, level, loop orientation.
    • Mission alignment — Anthropic is explicit about hiring people who care about AI safety as a real motivation.

    What they're looking for

    • A specific, non-generic reason you're motivated by Anthropic's mission — the recruiter screen is explicit about this filter.

  2. Round 2

    Technical phone screen

    60 minLive coding in a shared editor

    What it covers

    • A focused UI or JS problem — commonly a streaming/async component (streaming message bubbles, cancellable fetch, retry with backoff) given the product domain.
    • Follow-ups on edge cases, cancellation, error states.

    What they're looking for

    • Correct, considered code — not clever one-liners.
    • A visible stance on edge cases and failure modes before being prompted.

  3. Round 3

    Onsite: UI coding

    90 minLonger-form build

    What it covers

    • A UI build adjacent to the product — a streaming chat surface, a tool-use/argument panel, a token/cost estimator, a long-document viewer with cite-and-highlight.
    • React/TypeScript, from scratch, with an expectation of thoughtful component boundaries and real failure handling.

    What they're looking for

    • A build that respects streaming — tokens render as they arrive, cancellation works mid-stream, retries don't double-dispatch.
    • Accessibility baked in, not bolted on.

  4. Round 4

    Onsite: system design

    60 minWhiteboard / shared doc

    What it covers

    • A frontend-shape prompt grounded in the product: a chat with threads, a prompt playground with versioned prompts, a dense-document review surface, a tool-use trace viewer.

    What they're looking for

    • Specific trade-offs with specific conditions attached.
    • Honest about operational realities — streaming, cancellation, retries, rate limits, user-visible errors.

  5. Round 5

    Onsite: deep-dive on past work

    60 minConversation

    What it covers

    • One or two past projects, probed deeply. Decisions, trade-offs, outcomes.
    • A specific example of a time you deferred to a teammate's judgement, or changed your mind on a technical opinion.

    What they're looking for

    • Specifics, not adjectives. Numbers where numbers apply.
    • Visible intellectual honesty — a story about being wrong is a positive signal.

  6. Round 6

    Onsite: values / safety-aware thinking

    45–60 minConversation

    What it covers

    • How you reason about trade-offs with real-world risk — not just engineering risk, but user and societal risk.
    • Not a trick round. The signal is whether you've thought about these questions genuinely, not whether you have the 'right' answer.

    What they're looking for

    • Nuance. 'It depends on X, Y, Z' with specific conditions, not a confident one-liner.
    • Comfort sitting with uncertainty rather than fabricating confidence.

What each level expects

The bar you're being measured against — plus the failure modes candidates most often trip on at that level.

SDE 2 / mid

~2–4 years

Ships thoughtful features end to end with mentorship.

What they expect

  • Clean React/TypeScript with visible care for edge cases.
  • Comfortable with async/streaming primitives — AbortController, Streams, SSE.
  • Writes PRs small enough to read in one sitting, with descriptions that explain the why.

Common failure modes

  • Submitting work that's clever but not considered — the loop reads it as a culture flag.
  • Mission-alignment answers that read as rehearsed generic enthusiasm.

Senior

~5–8 years

Owns a technical area, mentors, writes docs/RFCs that outlive them.

What they expect

  • A system-design round where streaming/cancellation/retries are treated as first-class concerns.
  • Specific past-work ownership — 'I decided, I measured, I was wrong, I corrected'.
  • Visible writing practice.

Common failure modes

  • A system design that treats LLM output as instant and reliable rather than streaming and interruptible.
  • In the values round, a confident one-liner where nuance is the signal.

Staff

~8+ years

Technical direction across teams; drives multi-quarter initiatives.

What they expect

  • Peer-level discussion in the system-design round.
  • Multi-team leverage, evidenced by shipped work.
  • A visible, defensible philosophy with examples.

Common failure modes

  • Senior+ output rather than Staff leverage. The Staff bar is specifically about multiplying others.

How to crack it

Day-of advice. The specific moves that separate offers from no-offers when the content is already in your head.

  1. 1Spend meaningful time using Claude as a developer before the loop. Build a small app with the Anthropic SDK — a streaming chat, a tool-use demo, a long-document summariser. The specificity carries weight.
  2. 2Prepare one UI build that specifically respects streaming — tokens render as they arrive, cancellation works mid-stream, retries don't double-fire.
  3. 3Pre-write past-work stories that include a candid 'I was wrong, I changed' moment. The lack of one reads as a culture gap.
  4. 4For the values round, think genuinely about one real trade-off you've navigated — not with a prepared answer, with a prepared way of thinking out loud.
  5. 5Prepare one question per interviewer about the team's hardest current problem. Generic questions read as uninvested.

How to master it (over months, not days)

The longer-horizon work. These are the habits that pay off at Senior+ bars where cramming visibly fails.

  • Build and ship something real with the Anthropic SDK. The signal of 'I've actually used this' is distinct from 'I've read the docs'.
  • Make writing a daily practice — PR descriptions, specs, blog posts. The Senior+ bar at Anthropic is written-artefact-heavy.
  • Read the Anthropic research publications. The depth of thinking in the papers is the shape of thinking the loop rewards.
  • Learn Streams, SSE and AbortController deeply. These are the actual primitives behind streaming LLM UIs.
  • Build the habit of sitting with uncertainty before answering. The culture penalises confident wrong answers more than slow right ones.

Resources

On-site content for the technical prep, plus short-list of external links worth your time.

A note on sources. This guide synthesises public engineering blogs, published job descriptions, widely cited level frameworks, and public interview reports. Nothing here is insider knowledge or NDA-sensitive. Loops evolve — confirm the current shape with your recruiter.

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