Anthropic interview notes, page 10 of 32

Mid-sized

Most of these Anthropic write-ups come from Software Engineers (277), then Machine Learning Engineers (31) and Product Managers (10). The most reported rounds are the technical phone screen (129), the system design round (86), the behavioral / leadership round (45) and the hiring manager screen (17).

319 interview notes · updated Sep 2026

Anthropic·Software Engineer·Onsite - Behavioral / Leadership

May 2026

Behavioral screen for a SWE role at Anthropic. Just one question but it went pretty deep, they really wanted to trace through the whole arc of how you handled an ethical disagreement at work.

Tell me about a time you had a moral conflict with work you were assigned. How did you work through it internally, who did you bring it to, what was their role, and did the conversation actually change how you felt about it?

“This one has layers.”

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Anthropic·Software Engineer·Onsite - System Design / Architecture

May 2026

System design round at Anthropic focused entirely on low-level performance engineering. One question, very deep, and they clearly wanted to see if you actually understood the hardware implications of your design choices rather than just reciting theory.

Design a high-throughput hash table for use inside a tight compute kernel. Walk through your choice of open addressing vs chaining, load factor, probe sequence, and memory layout with an eye toward vectorization and cache behavior. Include how you'd use bitwise ops, prefetching, and alignment to minimize collisions and cache misses, and explain how you'd profile and validate the whole thing.

“This one went longer than I expected.”

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Anthropic·Software Engineer·Onsite - Behavioral / Leadership

May 2026

Anthropic engineering leadership interview, senior level, focused almost entirely on judgment and risk rather than anything technical. Three questions, all behavioral, and the vibe was clearly about whether you'd blow up a system chasing something clever.

Tell me about a time you turned down a technically exciting solution because the risk wasn't worth it.
Describe a situation where you disagreed with a strong-willed researcher or PM and had to work through it.
When you're working in a high-uncertainty environment, like unpredictable model behavior or requirements that keep shifting, how do you keep the team moving without locking in commitments you'll regret?

“This one tripped me up a bit because my instinct was to frame myself as the person who saved the day.”

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Anthropic·Software Engineer·Technical Phone Screen

May 2026

Anthropic software engineering interview that focused on image processing, starting with a basic Pillow implementation and then pushing into parallelism and Python's concurrency model. Pretty practical stuff but the second half caught me thinking harder than expected.

Given a batch of images, implement three operations: convert to grayscale, scale pixel values by a factor, and resize to a target resolution. Start with a standard library like Pillow.
How would you scale this image processing pipeline to handle a much larger batch efficiently, and why would you choose a process pool over a thread pool for this kind of work in Python?

“Pretty straightforward to get started.”

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Anthropic·Software Engineer·Onsite - Behavioral / Leadership

May 2026

Two rounds at Anthropic for a software engineering role: one focused on past projects and decision-making, the other almost entirely about AI safety beliefs and values. The values round was unlike anything I'd done before and I'm still not sure I nailed it.

Walk me through one or two major projects from your resume. What was the goal, what did you own, what tradeoffs did you make, and what would you do differently?
What's your personal view on advanced AI and AGI, and why do you think AI safety matters?
Tell me about a time you had to argue for or defend a responsible AI or safety-related position, either at work or outside of it.
Describe a disagreement you had with a collaborator over something non-technical, like a values or ethics question. How did it play out?

“This is the kind of question where you think you're ready and then halfway through your answer you realize you've been narrating instead of actually saying anything.”

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Anthropic·Software Engineer·Onsite - Behavioral / Leadership

May 2026

Behavioral round at Anthropic for a hardware engineering role. No technical questions at all, just a deep dive into how you lead cross-functional work and deal with the messiness that comes with it.

Walk me through a recent large-scale project that involved multiple teams or functions.
How did you handle conflicts that came up during the project?
How did you get alignment across teams with different priorities?
What metrics did you use to track progress or success on the project?

“I picked something I was proud of but in hindsight it was maybe too technically dense and they clearly did not care about the hardware side at all.”

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Anthropic·Software Engineer·Onsite - System Design / Architecture

May 2026

System design round at Anthropic for a software engineering role. The question was meaty and very specific to what Anthropic actually builds, so there was no hiding behind generic answers.

Design the backend architecture for a large-scale conversational AI system similar to Claude. Walk through model deployment, caching strategy, and safety validation layers.

“This one hit differently because you can't just recite a generic distributed systems answer.”

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Anthropic·Software Engineer·Technical Phone Screen

May 2026

Coding round at Anthropic for a software engineer role. One question, stack trace simulation, classic LeetCode territory but still easy to fumble if you're not careful with the off-by-one logic.

Given a list of stack-trace events where each event is either a function starting or ending at a given timestamp, compute the exclusive CPU time for each function. When one function calls another, the outer function's time should not count while the inner one is running.

“I knew this problem but still tripped up on the bookkeeping.”

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Anthropic·Software Engineer·Onsite - System Design / Architecture

May 2026

System design round at Anthropic for a software engineer role, focused entirely on a file deduplication system. The depth they expected was pretty intense, covering everything from low-level I/O edge cases to concurrency strategy.

Design a file deduplication program and walk through the real-world problems it would face in production. Cover things like permission errors, files changing mid-scan, path limits, symlink loops, memory/disk pressure, hash collisions, partial vs full hashing, concurrency, incremental rescans, and safe deletion strategies.

“This was basically one giant question with a dozen sub-questions folded inside it.”

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Anthropic·Software Engineer·Hiring Manager Screen

May 2026

Behavioral screen at Anthropic for a SWE role, just one question about meaningful work. Short conversation, not much to report.

Can you describe a project or piece of work that felt genuinely meaningful to you?

“Wasn't sure how deep to go.”

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