Anthropic Interview Questions
Practice 139 real Anthropic interview questions for 2026 — actual interviews with detailed solutions and targeted interview preparation for engineers and ML practitioners. This collection emphasizes Coding & Algorithms and System Design first, then Behavioral & Leadership, ML System Design, and Software Engineering Fundamentals. Expect heavy hands-on coding rounds, multi-threading and concurrency problems, end-to-end system design, plus behavioral questions tied to Anthropic’s mission and leadership choices. Roles covered include Software Engineer, Machine Learning Engineer, and Backend Engineer, with Software Engineer as the primary audience. Questions cluster by role: Software Engineer prompts repeat parallel and concurrent processing (parallel/batch image processors, concurrent web crawlers, crawler deduplication), prompt-and-tokenization work (prompt playgrounds, prompt-sharing, longest-match tokenizers), and algorithmic iterator/data-structure tasks. Machine Learning Engineer problems focus on production serving, inference routing and scheduling, model downloaders, caching (LRU), batch inference, and converting execution/state streams to traces. Backend, hiring-fit, and behavioral items probe culture fit and handling misaligned interviews. Prep by practicing timed coding, end-to-end design blueprints, tokenization and batching patterns, ML serving architectures, and concise STAR stories tied to Anthropic’s values.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Design a batch inference API
System Design: Async Inference Service API (POST Job, Poll for Results) Context You are designing an asynchronous inference service where clients subm...
Design a low-latency ML inference API
System Design: Low‑Latency ML Inference API (Real‑Time) Context You are designing an in‑region, synchronous inference API used by product surfaces (e....
How do you handle an LLM agents interview?
You have an interview on your agenda titled “Agents Interview.” Explain how you would approach this interview if it is about designing and evaluating ...
Design a scalable web crawler
System Design: Scalable Web Crawler Context Design a production-ready web crawler that discovers and downloads publicly accessible web pages at intern...
Improve concurrency beyond a single lock
You are given a simple multi-threaded component that protects all shared state with a single mutual-exclusion lock (mutex). Scenario A service has man...
Explain CPU-Bound vs I/O-Bound Work
Define CPU-bound and I/O-bound workloads. Then compare how multithreading, asynchronous I/O, and multiprocessing behave for each type of workload, esp...
Design an LLM-based binary classifier
Design a Binary Text Classifier Using Only a Log-Probability Scoring Helper Context You are building a binary text classifier without fine-tuning. You...
Design a model downloader
Design a system that distributes machine learning model artifacts from centralized storage to a large fleet of inference servers. The system should su...
Convert Samples into Event Intervals
You are given a time-ordered array samples, where samples[i] is the function name observed at integer timestamp i. Convert this trace into a list of e...
Detect runs and answer suffix queries
Given an array of comparable elements a[0..m-1] and an integer N: 1) Write a function that returns the maximum length of any run of consecutive equal ...
Design a scalable, reliable system
System Design: Global Photo/Video File Storage and Sharing ("CloudDrive") Context Design a scalable, highly reliable consumer service where users uplo...
How should you handle misaligned interviews?
A backend engineer prepared for a coding interview after the recruiter explicitly said the round would assess concurrency. The candidate chose Java as...
How would you scale batch image pipelines?
Design a system to process m input images with n pipelines, producing m×n outputs. - Pipelines are sequences of image operations (resize/rotate/filter...
Implement a crash-resilient LRU cache
Implement an LRU-based memoization helper with behavior similar to a standard Python LRU cache. You are given an interface like this: `python class LR...
How do you design an A/B experiment?
You have an interview on your agenda titled “Experiment Design.” You are asked to design an online experiment (A/B test) for a product change. Describ...
Implement a Batch Image Processor
Implement a program that applies basic image transformations to a batch of images. You are given a list of input image paths and, for each image, a se...
Implement a thread-safe producer–consumer buffer
Bounded Blocking Buffer with Shutdown and Timeouts You are asked to design and implement a thread-safe, fixed-capacity producer–consumer buffer that s...
Design a scalable network I/O service
System Design: High-Volume Network I/O Backend (Files and Streaming) Context Design a backend service that supports millions of users uploading and do...
Design a prompt-sharing platform
The interviewer gives you a fixed high-level architecture: client -> web server -> database. Do not spend time redrawing the whole system. Design the ...
Implement and analyze custom attention
Implement Scaled Dot-Product Attention in PyTorch (from scratch) Context You will implement a numerically stable, vectorized scaled dot-product attent...