Anthropic Interview Questions — Page 11

Anthropic·Software Engineer·Technical Phone Screen

May 2026

Interviewed for a software engineering role at Anthropic and got hit with the classic LRU cache design question. Not a bad experience, but the follow-ups on thread-safety and extending to TTL or LFU caught me a bit flat-footed.

Design and implement an LRU cache with get and put operations both running in O(1) average time. Walk through the data structure choices and implementation.

“I knew the hashmap plus doubly-linked list answer cold, so the base implementation went fine.”

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Anthropic·Software Engineer·Onsite - System Design / Architecture

May 2026

System design round at Anthropic for a software engineering role. The whole session was basically one big question about file deduplication that kept getting harder the more you answered it.

You have access to a massive file system spanning many directories. Design an algorithm to find all groups of byte-identical files. Walk through how you'd minimize I/O by filtering on file size first, then using partial hashing, then full hashing. How do you handle hash collisions, memory pressure, and parallelization?
How would you extend the deduplication system to handle incremental updates, meaning files being added or modified over time, without re-scanning everything from scratch?
How would you extend this design to work across multiple machines, not just a single file system?
Once duplicates are identified, how would you safely replace them with hard links or move them into content-addressed storage?

“The layered filtering approach felt natural to me: skip anything that doesn't share a size with at least one other file, then do a cheap partial hash on the first few KB, then full hash only the survivors.”

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Anthropic·Software Engineer·Recruiter / HR Screen

May 2026

Screening question for a software engineer role at Anthropic, just the one motivational question about why you want to work there specifically.

Why do you want to join Anthropic right now? What specifically about the mission, the work, or the culture connects to where your career is headed?

“This is the kind of question that sounds easy until you actually try to answer it without sounding generic.”

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Anthropic·Software Engineer·Onsite - Behavioral / Leadership

May 2026

Culture and behavioral round for a software engineer role at Anthropic. The whole thing centered on mission alignment and AI safety, which makes sense given the company, but it still felt more personal than a typical behavioral loop.

Why do you want to work at Anthropic specifically, and what draws you to this mission?
What does AI safety mean to you personally, and can you point to a real decision in your life or career that it influenced?
Tell me about a time you disagreed with your team or colleagues on something important. How did you handle it?
Describe a moral or ethical dilemma you faced at work and walk me through how you reasoned through it.

“I had an answer ready but it felt thin the moment I said it out loud.”

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Anthropic·Software Engineer·Technical Phone Screen

May 2026

Anthropic software engineer interview with a warm-up coding round where you pick your poison: web crawler or image processing. Pretty open-ended, which sounds nice until you realize you have to drive the whole thing yourself.

You're given a choice: implement a web crawler starting from a URL (fetching pages, extracting links, staying on the same domain, no revisits) OR implement an image processing routine over a 2D pixel grid (flood fill, region counting, boundary detection, or convolution). Pick one and code it end-to-end, then discuss how you'd extend it.

“I went with the web crawler because I figured I had more to say about it.”

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Anthropic·Software Engineer·Onsite - System Design / Architecture

May 2026

System design round at Anthropic for a software engineering role, focused entirely on architecting the frontend of a cross-platform desktop AI chat app. Brutal scope: they wanted everything from IPC sandboxing to plugin systems to E2E encryption in one session. Left feeling like I'd covered maybe 60% of what they were actually looking for.

Design the frontend architecture for a cross-platform desktop conversational AI application, covering core modules, state management, performance, security, observability, build/deployment, testing, accessibility, and extensibility.
What are the trade-offs between Electron, Tauri, and native WebView stacks for a desktop AI chat application?
How would you handle state management and persistence for chat sessions, including offline support, encryption, and cloud sync conflict resolution?
How would you approach performance in long conversations, specifically around virtualized rendering and incremental display of streaming tokens?
How would you design the security model for a desktop AI app, covering IPC boundaries, sandboxing, filesystem/network permissions, secret handling, and content sanitization?
How would you build a plugin system and theming layer for a desktop AI application while maintaining security and extensibility?
What is your approach to observability and privacy-preserving analytics in a desktop application where users have strong privacy expectations?

“The scope of this thing was genuinely disorienting.”

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Anthropic·Software Engineer·Onsite - System Design / Architecture

May 2026

System design round at Anthropic for a software engineering role, focused entirely on building a background processing backend for LLM prompts. The question had a ton of surface area and the follow-up on streaming and cancellation caught me pretty flat-footed.

Design a background processing system for LLM prompts where clients submit jobs via an API and retrieve results through polling or callbacks. Cover job queuing, prioritization, worker pools, model routing, prompt versioning, idempotency, retries, dead-letter queues, result storage, and observability. Also address scaling, cost control, rate limiting, PII handling, and SLAs.
How would you extend the system to support streaming partial outputs from the model back to the client, and allow clients to cancel in-flight jobs?

“This thing has so many moving parts I didn't know where to start.”

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Anthropic·Software Engineer·Onsite - System Design / Architecture

May 2026

System design round at Anthropic for a SWE role, focused entirely on building an inference batching system for a single GPU. Pretty deep technically and the follow-up questions kept coming.

Design an inference batching system for a single GPU that handles up to 100 inputs per batch, where users are waiting synchronously for responses. How do you maximize GPU utilization under compute constraints?
How would you return responses to individual users when requests are batched together on the backend?
What are the main trade-offs in this batching design, and where does it break down?
How would you scale this system beyond a single GPU?

“This one took me a minute to even orient myself.”

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Anthropic·Software Engineer·Technical Phone Screen

May 2026

Anthropic software engineer interview that was basically a filesystem problem dressed up as a systems question. More depth required than I expected, especially around the I/O optimization side of things.

Given access to a directory tree, write code to find all groups of files that have identical byte content. Walk through your approach to minimizing disk I/O, handling large files, permission errors, and symbolic links.

“I started with hashing right away and the interviewer immediately asked why I wasn't grouping by size first.”

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Anthropic·Software Engineer·Hiring Manager Screen

May 2026

Interviewed for an account manager role at Anthropic. One question, pretty short interaction, but it made me think more than I expected.

How much ownership do you take over a deployment?

“Stumbled a bit here because I wasn't sure if they wanted a process answer or a mindset answer.”

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