Anthropic Coding & Algorithms Interview Questions

Anthropic Coding & Algorithms interview questions tend to skew practical and systems-minded rather than purely contrived puzzles. Expect live, timed coding rounds (often in a shared Python environment or CodeSignal), system-design-style problems for scaling and reliability, and behavioral questions tied to safety and collaboration. Interviewers evaluate problem decomposition, correctness, edge-case handling, performance trade-offs, code clarity and modularity, and how you reason about concurrency, data mutation, and robustness under changing requirements. Deep follow-ups are common: a working solution is a starting point, not the finish line. For interview preparation focus on building polished, testable implementations of multi-stage problems (for example in-memory stores, streaming/aggregation tasks, or concurrent data structures), practicing clear verbal articulation of trade-offs, and rehearsing concise safety- and values-aligned stories. Time-boxed mock interviews in the same tools you’ll use, steady practice with Python standard library idioms, and walking through post-solution optimizations will pay off. Emphasize readability, small iterative steps, and how you validate and harden code — those habits map directly to what Anthropic seeks.

79 Questions 1 Company07.08.2026
Showing 19 results
Role
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Anthropic
Medium
Software Engineer Locked

Implement a Parallel Image Processor

This question evaluates understanding of parallel and process-based concurrency, batch image-processing pipelines, transform correctness, and per-job ...

Coding & Algorithms
31
0
330 people solved
Apr 3, 2026
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Anthropic
Medium
Software Engineer

Implement Parallel Image Processing

Build an image-processing utility in Python using the Pillow library. You are given a collection of image file paths and an output directory. For each...

Coding & Algorithms
2
0
13 people solved
Mar 2, 2026
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Anthropic
Medium
Software Engineer Locked

Implement crawler and file deduplication

This question evaluates competencies in concurrent programming, web crawling and graph traversal, thread safety, rate limiting, I/O-efficient file ded...

Coding & Algorithms
11
0
97 people solved
Feb 28, 2026
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Anthropic
Hard
Software Engineer

Find Duplicate Files by Content

You are given a list of directory descriptions. Each description has the following format: root_directory file_name_1(content_1) file_name_2(content_2...

Coding & Algorithms
0
0
3 people solved
Feb 21, 2026
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Anthropic
Hard
Software Engineer Locked

Design stack with O(1) minimum query

This question evaluates understanding of stack-based data structures, constant-time operation constraints, and handling edge cases such as empty queri...

Coding & Algorithms
57
0
432 people solved
Feb 1, 2026
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Anthropic
Medium
Software Engineer

Compute exclusive times and call stack from logs

Design an algorithm that, given a single-threaded program's execution log, computes per-function exclusive durations and reconstructs the active call ...

Coding & Algorithms
14
0
174 people solved
Sep 6, 2025
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Anthropic
Medium
Software Engineer

Design high-throughput hashing for kernels

Design a high-throughput hash-based lookup to be called inside a tight kernel. Choose between open addressing and chaining, specify the load factor, p...

Coding & Algorithms
17
0
179 people solved
Sep 6, 2025
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Anthropic
Medium
Software Engineer

Implement file deduplication at scale

Implement a command-line tool to find duplicate files in a directory tree. Use OS/pathlib primitives to recursively enumerate files. Apply prefilters ...

Coding & Algorithms
18
0
152 people solved
Sep 6, 2025
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Anthropic
Medium
Software Engineer

Simulate stack traces from logs

Given a list of log entries describing function calls, each formatted as "<id> <event> <timestamp>" where event ∈ {START, END} and timestamps are inte...

Coding & Algorithms
51
0
471 people solved
Sep 6, 2025
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Anthropic
Medium
Software Engineer

Implement a recency-eviction bounded cache

Implement an in-memory key–value store with a fixed capacity N that uses recency-based eviction. Support: get(key) -> value or -1 if missing, and put(...

Coding & Algorithms
16
1
211 people solved
Sep 6, 2025
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Anthropic
Medium
Software Engineer

Implement hostname-restricted web crawler

Implement a single-threaded web crawler that, given a starting URL startUrl and an interface getUrls(url) that returns all hyperlinks on the page at u...

Coding & Algorithms
10
0
166 people solved
Sep 6, 2025
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Anthropic
Medium
Machine Learning Engineer

Implement an extensible prefix tree

Implement a prefix tree (trie) supporting insert(word), search(word), startsWith(prefix), countPrefix(prefix), and erase(word). Optimize for time and ...

Coding & Algorithms
44
0
317 people solved
Aug 14, 2025
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Anthropic
Medium
Software Engineer

Detect n-length consecutive sequences

Given an unsorted collection of integers and a parameter n > 0, determine whether there exists a set of n distinct integers that form a run of consecu...

Coding & Algorithms
23
0
216 people solved
Aug 13, 2025
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Anthropic
Medium
Software Engineer

Compute matrix trace and support updates

Given an n x n integer matrix M, implement a function trace (M) that returns the sum of its main diagonal. Follow-ups: (a) If you receive q point upda...

Coding & Algorithms
15
0
185 people solved
Aug 13, 2025
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Anthropic
Medium
Software Engineer

Solve programming task with follow-ups

Question Pure programming problem solving: implement the core algorithmic solution, then extend it to ( 1) support a constraint of consecutive N eleme...

Coding & Algorithms
14
0
143 people solved
Aug 4, 2025
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Anthropic
Medium
Software Engineer

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 ...

Coding & Algorithms
18
0
250 people solved
Jul 28, 2025
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Anthropic
Medium
Machine Learning Engineer

Implement cluster status tracker

Implement a cluster status tracker. Design a class with methods: update(nodeId, status, timestamp) to record node status updates that may arrive out o...

Coding & Algorithms
19
0
259 people solved
Jul 27, 2025
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Anthropic
Medium
Software Engineer

Find and remove duplicate files

Given a directory tree that may not fit in memory, detect and optionally remove duplicate files. Define the algorithm, including how you handle very l...

Coding & Algorithms
22
0
166 people solved
Jul 26, 2025
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Anthropic
Medium
Software Engineer

Find the Slowest Function from Profiler Events

You are given a time-ordered profiler event log for a single-threaded program. Each event is one of: - START functionName timestamp: execution enters ...

Coding & Algorithms
1
0
14 people solved
Jun 17, 2025

Frequently Asked Questions

How hard are Anthropic Coding & Algorithms interview questions?
Anthropic’s coding and algorithms rounds are generally described as challenging but practical: they test core algorithmic thinking under time pressure rather than obscure trick questions. Expect problems that evaluate data structures, complexity reasoning, and the ability to produce clean, testable code in a shared environment (often Python). Rounds are timed and may feel brisk, so interviewers look for correct, readable solutions and sound tradeoffs rather than clever one‑liners. Candidates frequently report industrial-style tasks that escalate in complexity, which rewards steady problem decomposition and careful edge‑case handling.
What is the typical interview process and where do Coding & Algorithms questions appear?
For software roles at Anthropic, coding and algorithmic questions commonly appear in the initial online assessment and in one or more live technical rounds during the onsite loop. The process often starts with a recruiter screen, a timed coding challenge (e.g., CodeSignal), then one or two live coding interviews plus system design and behavioral rounds during the onsite. Coding segments focus on algorithmic problem solving, debugging and small project-style tasks, while later technical rounds may connect those problems to design or team-specific work. Expect interviews to be organized by the org you apply to (Research vs Applied).
How should I schedule my preparation for Anthropic Coding & Algorithms interviews?
A focused 4–8 week timeline is effective: begin with two weeks of core data structures and algorithm review (arrays, strings, trees, graphs, hashing, sorting, and complexity), followed by two weeks of timed practice on platforms that mimic assessments (practice CodeSignal-style tasks and full-length challenges). Reserve the final 1–2 weeks for mock live interviews, system design refreshers, and polishing language-specific idioms and quick I/O in Python. Sprinkle daily short debugging and read‑your‑own‑code sessions to improve clarity and speed. Adjust intensity based on role seniority and your baseline skills.
Which subtopics within Coding & Algorithms should I prioritize?
Prioritize fundamentals that interviewers use to judge practical engineering ability: arrays and strings, hashing, trees and graph traversals, dynamic programming basics, sorting and selection, and complexity analysis. Equally important are problem decomposition, writing testable code, handling edge cases and nulls, and explaining time/space tradeoffs. For Anthropic specifically, practice implementing small in‑memory systems or multi-step tasks that grow in complexity, and be comfortable with Python standard library tools and fast I/O. Performance considerations and readable, maintainable code are weighed alongside algorithmic correctness.
What are the most helpful tips and common pitfalls to avoid?
Communicate your thought process clearly, start with a correct brute force approach, and iterate toward optimizations while checking edge cases; interviewers reward clarity over premature cleverness. Write modular, testable code and run small examples to validate assumptions. Manage time: if stuck, state tradeoffs and pivot to a simpler, working solution. Common pitfalls include ignoring input constraints, failing to handle nulls or boundaries, and producing unreadable one-off solutions. Also be ready to discuss design decisions and tradeoffs rather than only delivering a final answer.

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