Anthropic Interview Questions
Reconstructed from 560 verified candidate reports across 49 questions. Nov 2024 – Sep 2026.
This page is a live view of every Anthropic interview question AceOffer has indexed — pulled from candidate reports, not invented from job descriptions or one founder’s memory. Every question shows how many times it’s been reported and when it was last seen. The catalog gets a refresh pass every month.
AceOffer is not affiliated with, endorsed by, or sponsored by Anthropic. Questions are reconstructed from interview experiences candidates shared, not from Anthropic materials.
What Anthropic pays: reported offers →Key facts
- •49 distinct Anthropic interview questions indexed
- •560 candidate reports across the catalog
- •Most reported: File Deduplication — 50× (last seen September 2026)
- •Round mix across candidate reports: behavioral 31%, coding 27%, system design 20%, phone screen 12%, online assessment 8%
- •Most common coding topics: stateful class design (5 questions), time-based state (expiry, TTL, snapshots) (4 questions), parsing structured text (3 questions)
- •27 of the 49 questions were last reported in Jul–Sep 2026
- •Reports span Nov 2024 – Sep 2026
- •Refreshed monthly · last updated September 2026
Browse Anthropic interviews by topic
Deep-dive guides
The Anthropic loop, from candidate reports
Anthropic's loop is recruiter screen → a CodeSignal-style 90-minute Python coding assessment (not every candidate gets one) → 1–2 phone screens → a virtual onsite of four or five rounds. The behavioral round at Anthropic is unusually deep and weighted: the interviewer probes AI safety alignment with specific hypothetical scenarios, and candidates report being asked 'why Anthropic over OpenAI' with the expectation of a substantive answer that goes beyond mission slogans. The Web Crawler phone screen is the most-reported question by a wide margin — it's effectively a filter. In 2026 reports, system design increasingly means reviewing a flawed design document, and some loops add an AI-assisted coding round. ML / Research Engineer roles add an inference-API system design.
What does Anthropic ask in each interview round?
Anthropic interviews span 6 distinct round types, broken down below. Counts reflect distinct questions per round, not number of times asked. Frequencies on individual question cards show how many candidates reported getting that specific question.
Two-way conversations. Anthropic in particular probes AI safety alignment hard; OpenAI probes mission-fit and shipping velocity.
60 minute design rounds. Interviewers push hard on the specific dimension their team cares about (storage at scale, real-time fan-out, multi-tenancy).
Implement forward + backward from scratch (NumPy), debug a planted-bug transformer, or design an ML system. Math + code + system thinking.
60–75 minute live coding rounds. Multiple sub-problems progressing in difficulty. Test harness usually provided.
Take-home or proctored 90-minute online assessment before the loop. Used as a filter — not weighted in the final decision once you're in the onsite.
60–90 minute coding or system design over CoderPad or similar. Pass bar is correctness + clean communication; brilliance isn't required.
Which Anthropic interview questions come up most?
These are the Anthropic questions reported most across the loops we’ve indexed, sorted by candidate-report frequency.
| Question | Round | Reported | Last seen |
|---|---|---|---|
| File Deduplication | Coding | 50× | September 2026 |
| Web Crawler | Phone Screen | 48× | September 2026 |
| Culture Fit / Behavioral Questions | Behavioral | 43× | September 2026 |
| Profiling / Stack Trace Analysis | Coding | 42× | September 2026 |
| Inference API System Design | System Design | 41× | September 2026 |
| Why Anthropic? | Behavioral | 33× | September 2026 |
| AI Safety Culture Fit | Behavioral | 32× | September 2026 |
| Image Processing Pipeline | Coding | 25× | September 2026 |
| Most Impactful Project / HM Behavioral | Behavioral | 24× | August 2026 |
| Project Deep Dive / Technical Presentation | Behavioral | 21× | August 2026 |
The full index is below, or browse the Anthropic catalog →
Every Anthropic interview question we’ve indexed
All 49, grouped by round and sorted by how often candidates reported them. Each links to the question, its reported follow-up count, and when it was last seen.
Behavioral (12)
- Culture Fit / Behavioral Questions — reported 43×, last seen September 2026
- Why Anthropic? — reported 33×, last seen September 2026
- AI Safety Culture Fit — reported 32×, last seen September 2026
- Most Impactful Project / HM Behavioral — reported 24×, last seen August 2026
- Project Deep Dive / Technical Presentation — reported 21×, last seen August 2026
- Project Feasibility / Failure BQ — reported 9×, last seen April 2026
- Career Plan / Work Preferences — reported 4×, last seen June 2026
- Thoughts on Anthropic as a Company / HM Discussion — reported 3×, last seen September 2026
- Most Challenging Project (Recruiter Chat) — reported 2×, last seen March 2026
- Open-Source AI Safety / Community Benefit Discussion — reported 2×, last seen March 2026
- Open-ended Research Question (Take-home) — reported 1×, last seen June 2026
- Dataset Analysis with Cloud Capacity Management — reported 1×, last seen June 2026
System Design (11)
- Inference API System Design — reported 41×, last seen September 2026
- ML Model Distribution / Deployment System Design — reported 16×, last seen August 2026
- Prompt Playground System Design — reported 15×, last seen August 2026
- Batch Inference System Design — reported 12×, last seen August 2026
- Chat System Design (1-on-1) — reported 7×, last seen August 2026
- GPU Cluster / Inference Infrastructure System Design — reported 7×, last seen August 2026
- GPU Allocation for Mixed Large/Small Model Inference — reported 4×, last seen September 2026
- Roofline Model Analysis — reported 4×, last seen September 2026
- System Design Doc Review — reported 3×, last seen April 2026
- Stream Large File to Many Machines — reported 2×, last seen June 2026
- Amusement Park / Sharing System Product Design — reported 1×, last seen April 2026
MLE (9)
- NumPy Debugging — reported 3×, last seen June 2026
- Custom Attention / Einsum Algorithm (ML Programming) — reported 2×, last seen July 2025
- Data Batcher with Weighted Sampling — reported 2×, last seen April 2026
- Neural Network Forward and Backward Pass Implementation — reported 2×, last seen July 2025
- Debug GRPO / RL Training Code — reported 2×, last seen March 2026
- Multi-layer Pattern Performance with Memory Constraints — reported 1×, last seen September 2025
- LLM-Based Binary Classifier Design — reported 1×, last seen July 2025
- A100 Matrix Multiplication Performance Modeling — reported 1×, last seen September 2025
- Sample-Aspect Double Descent Experiment Design — reported 1×, last seen April 2026
Coding (7)
- File Deduplication — reported 50×, last seen September 2026
- Profiling / Stack Trace Analysis — reported 42×, last seen September 2026
- Image Processing Pipeline — reported 25×, last seen September 2026
- Distributed Mode/Median — reported 15×, last seen September 2026
- LRU Cache — reported 10×, last seen June 2026
- AI-Assisted Coding: Four Pull Requests with Claude Code — reported 4×, last seen September 2026
- Bootloader with Loop Detection — reported 3×, last seen July 2026
OA (6)
- Banking System (OA) — reported 17×, last seen July 2026
- In-Memory Database — reported 12×, last seen July 2026
- Task Management System — reported 5×, last seen August 2026
- VLIW / TPU / Kernel Optimization Assignment — reported 4×, last seen December 2025
- Recipe Manager — reported 3×, last seen April 2026
- Cloud File Storage System — reported 3×, last seen July 2026
Phone Screen (4)
- Web Crawler — reported 48×, last seen September 2026
- Tokenizer Implementation — reported 11×, last seen July 2026
- Claude Agent Loop with Multi-Step Tool Calling — reported 3×, last seen August 2026
- Consecutive Event / Sample Detection — reported 3×, last seen December 2025
Read two Anthropic questions free
Full problem statements, candidate-reported follow-ups, and walkthroughs. No signup needed.
Crawl every page within the same hostname using a provided link helper. Start single-threaded, then make it concurrent. The most-reported Anthropic question by a wide margin.
Design a prompt playground — stateless conversation turns, share-conversation feature, very large prompts. The interviewer probes UX, frontend state, and the share mechanism in depth.
Live-debug a buggy GRPO training script. Three planted bugs — softmax before multinomial, epsilon-less std, and the importance-sampling ratio formula — then RL-theory follow-ups on PPO clipping and mini-epoch policy drift. The Anthropic Research / MLE signature debug round.
- •On the behavioral round: come with one specific Anthropic alignment paper or recent decision (RSP, Constitutional AI, the deprecation policy) and connect it back to your own work — generic safety enthusiasm gets flagged
- •On Web Crawler: progressive complexity wins — solve single-threaded clearly first, then propose the concurrent extension with the interviewer's blessing. Don't dive into concurrency immediately
- •On Inference API system design: distinguish the routing layer (cheap, stateless) from the model serving layer (expensive, GPU-pinned) early, then build from there
- •Quote your work back as 'I made this technical decision because of X tradeoff' — not 'I worked on Y' — Anthropic's deep-dive round is grading reasoning, not titles
- •Treating the AI safety culture round as a soft round and giving a corporate-policy answer — gets flagged as 'low alignment signal' and reported as a primary loss reason
- •On Web Crawler: jumping to a concurrent solution without verifying the single-threaded version against the test cases first
- •Skipping the URL normalization step on Web Crawler (fragments, query params, trailing slashes) — one report calls out fragments specifically
- •On Inference API: conflating the model-routing problem with the model-serving problem; not distinguishing latency-sensitive (real-time) from throughput-optimized (batch) workloads
- •On the project deep-dive: presenting WHAT you built without articulating the alternatives you considered and why you rejected them
Get the full Anthropic catalog
Every question. Every candidate-reported follow-up. The mistakes that sink people, and what passers do instead. Monthly refresh.
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