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 20 results
Role
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Anthropic
Hard
Software Engineer

Build a Progressive Banking Ledger

Build a Progressive Banking Ledger The source reports the four feature stages but not exact ledger semantics. The APIs, event priorities, cashback tim...

Coding & Algorithms
2
0
43 people solved
Jul 8, 2026
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Anthropic
Medium
Software Engineer

Banking System Simulation

Banking System Simulation You are building an in-memory banking system that is driven by a time-ordered stream of operations. Implement the system so ...

Coding & Algorithms
6
0
57 people solved
Jun 23, 2026
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Anthropic
Hard
Software Engineer

Build a Progressive Employee Tracker

Build a Progressive Employee Tracker The source reports four tracker stages but not exact calls or failure values. The command driver and ordering rul...

Coding & Algorithms
5
0
52 people solved
Jul 8, 2026
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Anthropic
Medium
Software Engineer

Generate Function Profiling Events from Stack Samples

Generate Function Profiling Events from Stack Samples You receive timestamped call-stack samples in increasing timestamp order. Each sample is (timest...

Coding & Algorithms
6
0
66 people solved
Apr 13, 2026
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Anthropic
Hard
Software Engineer

Convert Stack Samples into Trace Events

Convert Stack Samples into Trace Events The source reports converting sampled call stacks into trace events but does not provide the exact tuple forma...

Coding & Algorithms
2
0
36 people solved
Jul 8, 2026
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Anthropic
Hard
Software Engineer

Calculate Streaming Token Usage Costs

Calculate Streaming Token Usage Costs Implement a usage calculator for language-model API requests. Input and output tokens have different prices, and...

Coding & Algorithms
2
0
18 people solved
Jul 8, 2026
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Anthropic
Medium
Software Engineer Locked

Time-Based Key-Value Store

This question evaluates the ability to design a data structure that supports versioned storage and efficient point-in-time lookups. It tests binary se...

Coding & Algorithms
1
0
9 people solved
Jun 23, 2026
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Anthropic
Hard
Software Engineer

Build a Progressive Cloud Storage System

Build a Progressive Cloud Storage System The source reports four storage stages but not the exact API. The command encoding, quota accounting, compres...

Coding & Algorithms
1
0
25 people solved
Jul 8, 2026
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Anthropic
Hard
Software Engineer

Implement a Longest-Match Tokenizer

Implement a Longest-Match Tokenizer The source reports longest matching, unknown-token handling, and an optional unknown-merging extension. The exact ...

Coding & Algorithms
3
0
21 people solved
Jul 8, 2026
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Anthropic
Hard
Software Engineer

Build a Versioned In-Memory Database

Build a Versioned In-Memory Database The source reports a four-stage in-memory database exercise but does not provide its exact method signatures. The...

Coding & Algorithms
2
0
18 people solved
Jul 8, 2026
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Anthropic
Medium
Software Engineer

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...

Coding & Algorithms
722
4
5128 people solved
Mar 13, 2026
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Anthropic
Hard
Software Engineer Locked

Implement a Time-Aware Task Manager

This question evaluates the ability to design and implement in-memory data structures and algorithms for time-aware state management, including per-us...

Coding & Algorithms
6
0
34 people solved
May 17, 2026
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Anthropic
Medium
Software Engineer

Implement crawler, dedup, and persistent LRU

Implement crawler, dedup, and persistent LRU LeetCode 1236. Web Crawler: Crawl web pages starting from a given URL within the same hostname. LeetCode ...

Coding & Algorithms
114
0
788 people solved
Aug 4, 2025
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Anthropic
Hard
Software Engineer

Simulate Threshold Infection Efficiently

Simulate Threshold Infection Efficiently You are given an m x n grid, a set of initially infected cells, and an integer threshold k. Time advances in ...

Coding & Algorithms
2
0
13 people solved
Jul 8, 2026
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Anthropic
Medium
Software Engineer Locked

Implement Task Management and Duplicate Detection

This question evaluates implementation and system-design skills across two problems: an in-memory task management service (CRUD operations, prioritize...

Coding & Algorithms
3
0
17 people solved
May 16, 2026
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Anthropic
Medium
Software Engineer Locked

LRU Cache

This question evaluates a candidate's ability to design a data structure combining a hash map with a doubly linked list to achieve constant-time acces...

Coding & Algorithms
2
0
13 people solved
Jun 23, 2026
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Anthropic
Medium
Software Engineer Locked

Word Search in a Letter Grid

This question evaluates a candidate's ability to search for multiple target words within a grid of letters using depth-first traversal and backtrackin...

Coding & Algorithms
0
0
14 people solved
Jun 23, 2026
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Anthropic
Medium
Software Engineer Locked

Account Balance with Expiring Grants

This question evaluates the ability to design a data structure that tracks time-limited credit grants, prioritizing expiration order during spending a...

Coding & Algorithms
0
0
13 people solved
Jun 23, 2026
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Anthropic
Hard
Software Engineer Locked

Implement Persistent Memoization LRU Cache

This question evaluates knowledge of memoization, LRU cache semantics, deterministic cache-key construction from positional and keyword arguments, JSO...

Coding & Algorithms
9
0
69 people solved
May 23, 2026
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Anthropic
Hard
Software Engineer Locked

Implement a hierarchical file store

This question evaluates proficiency in modeling hierarchical file systems, path parsing and manipulation, managing mutable file contents, and analyzin...

Coding & Algorithms
4
0
20 people solved
May 12, 2026

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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