Anthropic
AI safety and research company behind Claude, focusing on constitutional AI.
5 Rounds
~20 Days
Very Hard
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Backend Engineer
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Behavioral
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medium
Anthropic heavily values 'Helpful, Honest, and Harmless' (HHH). Tell me about a time you had to trade off between shipping a feature quickly and ensuring system safety or reliability.
#Safety
#Trade-offs
#Decision Making
Backend Engineer
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Behavioral
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medium
Tell me about a time you worked closely with researchers or data scientists to deploy a complex model or algorithm to production.
#Cross-functional
#Communication
#MLOps
Backend Engineer
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Behavioral
•
medium
Describe a time you had to debug a complex distributed systems failure in production. What was your methodology?
#Debugging
#Incident Response
#Distributed Systems
Backend Engineer
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Behavioral
•
medium
How do you handle situations where product requirements are highly ambiguous or rapidly changing, which is common in the fast-paced AI industry?
#Ambiguity
#Agile
#Communication
Backend Engineer
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Behavioral
•
medium
Tell me about a time you disagreed with a technical decision made by your team or manager. How did you handle it, and what was the outcome?
#Conflict Resolution
#Leadership
#Communication
Backend Engineer
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Behavioral
•
medium
Describe a project where you had to significantly optimize the performance (latency, throughput, or cost) of a backend system. What metrics did you use?
#Performance Optimization
#Impact
#Metrics
Backend Engineer
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Behavioral
•
easy
Why Anthropic? With so many AI labs like OpenAI, DeepMind, and Meta, what specifically draws you to our mission and technical approach?
#Motivation
#Company Knowledge
#Alignment
Backend Engineer
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Coding
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medium
Implement a thread-safe Rate Limiter using the Token Bucket algorithm. It should support multiple users and handle concurrent requests efficiently.
#Concurrency
#Data Structures
#API Design
Backend Engineer
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Coding
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hard
Write an asynchronous task scheduler in Python (using asyncio) or Rust (using tokio) that executes a DAG (Directed Acyclic Graph) of tasks with maximum concurrency.
#Graph Theory
#Asynchronous Programming
#Concurrency
Backend Engineer
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Coding
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hard
Implement a streaming JSON parser that can take chunks of a JSON string (as they are generated by an LLM) and yield valid parsed objects as soon as they are complete.
#Parsing
#State Machines
#String Manipulation
Backend Engineer
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Coding
•
medium
Implement a thread-safe LRU Cache with a Time-To-Live (TTL) for each item. Expired items should not be returned and should be cleaned up efficiently.
#Hash Map
#Linked List
#Concurrency
Backend Engineer
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Coding
•
hard
Given a stream of tokens (strings), implement a data structure to efficiently find the top K most frequent tokens in a sliding window of the last N minutes.
#Streaming Data
#Heaps
#Sliding Window
Backend Engineer
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Coding
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medium
Implement a Trie (Prefix Tree) that supports inserting strings, searching for exact matches, and finding all strings that share a given prefix. Optimize it for memory.
#Trees
#String Manipulation
#Memory Optimization
Backend Engineer
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Coding
•
hard
Write a function to merge K sorted asynchronous streams of data into a single sorted stream. You cannot load all data into memory at once.
#Heaps
#Asynchronous Programming
#Streaming
Backend Engineer
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Coding
•
medium
Implement a bounded blocking queue. It should support enqueue and dequeue operations, blocking when full or empty, respectively.
#Concurrency
#Synchronization
#Thread Safety
Backend Engineer
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Coding
•
hard
Given a string representing a user prompt, find the longest repeating substring. This is useful for detecting repetitive loops in context windows.
#String Manipulation
#Dynamic Programming
#Suffix Trees
Backend Engineer
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Coding
•
medium
Implement an in-memory Event Bus (Pub/Sub system) where publishers can emit events and subscribers can listen to specific event types using regex patterns.
#Design Patterns
#Concurrency
#String Matching
Backend Engineer
•
Coding
•
hard
Write a program to justify text. Given an array of words and a max width, format the text such that each line has exactly max width characters and is fully (left and right) justified.
#String Manipulation
#Array
#Simulation
Backend Engineer
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Coding
•
medium
Given a massive log file of API requests, write a script to find the 99th percentile latency. The file is too large to fit into memory.
#Data Processing
#Approximation Algorithms
#File I/O
Backend Engineer
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Coding
•
medium
Implement a deep copy function for a complex graph data structure that may contain cycles. Ensure that nodes are duplicated correctly without infinite loops.
#Graph Theory
#Recursion
#Hash Map
Backend Engineer
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System Design
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hard
Design a scalable rate-limiting service for the Claude API that can handle millions of requests per minute across globally distributed data centers.
#Distributed Systems
#Redis
#High Availability
Backend Engineer
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System Design
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hard
Design a real-time streaming inference API for an LLM. How do you handle connection drops, partial token generation, and backpressure?
#Server-Sent Events (SSE)
#WebSockets
#Streaming
#Network Protocols
Backend Engineer
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System Design
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hard
Design a distributed prompt caching layer to optimize LLM inference costs. How do you handle cache invalidation and eviction for variable-length context windows?
#Caching
#Distributed Systems
#Optimization
Backend Engineer
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System Design
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hard
Design a system to schedule and batch LLM inference requests across a cluster of GPUs to maximize throughput while respecting latency SLAs.
#Batching
#Resource Scheduling
#Queueing Theory
Backend Engineer
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System Design
•
hard
Design a telemetry and observability system for LLM safety guardrails. It needs to ingest billions of events per day and allow for real-time alerting on policy violations.
#Data Ingestion
#Stream Processing
#Observability
Backend Engineer
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System Design
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medium
Design an asynchronous web scraper for training data collection. It must respect robots.txt, handle rate limits, and scale to scrape millions of domains daily.
#Web Scraping
#Distributed Systems
#Concurrency
Backend Engineer
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System Design
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hard
Design an abuse detection system that monitors API usage patterns to detect and block malicious actors (e.g., prompt injection attacks, DDOS, account sharing) in near real-time.
#Security
#Stream Processing
#Machine Learning Infrastructure
Backend Engineer
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System Design
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medium
Design a highly available key-value store to maintain user session history (chat logs) for Claude. It must support high write throughput and fast sequential reads.
#Databases
#Replication
#Data Modeling
Backend Engineer
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System Design
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medium
Design a system to handle long-running asynchronous model fine-tuning jobs. How do you manage state, handle node failures, and provide progress updates to users?
#Job Scheduling
#State Machines
#Fault Tolerance
Backend Engineer
•
System Design
•
hard
Design a Vector Database architecture for Retrieval-Augmented Generation (RAG). How do you scale the index for billions of embeddings while maintaining low-latency ANN (Approximate Nearest Neighbor) search?
#Vector Databases
#Machine Learning Infrastructure
#Search
Backend Engineer
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System Design
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medium
Design a distributed ID generator that generates unique, k-sortable (time-ordered) 64-bit integers at a scale of millions per second.
#Distributed Systems
#Algorithms
#Scalability
Backend Engineer
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Technical
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medium
Explain how Python's Global Interpreter Lock (GIL) impacts concurrent API requests. How would you architect a high-throughput Python backend to bypass these limitations?
#Python
#Concurrency
#Multiprocessing
Backend Engineer
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Technical
•
medium
How do you handle backpressure in a distributed messaging queue when the consumers (e.g., GPU inference nodes) are overwhelmed?
#Message Queues
#System Reliability
#Backpressure
Backend Engineer
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Technical
•
hard
How would you optimize a Rust backend for high-throughput, low-latency network I/O? Discuss memory allocation, async runtimes, and socket tuning.
#Rust
#Networking
#Performance Optimization
Backend Engineer
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Technical
•
hard
Describe how you would implement zero-downtime deployments for a backend service that maintains long-lived stateful streaming connections (like SSE for LLM responses).
#Deployments
#Networking
#High Availability
Difficulty Radar
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Senior EngineerFocuses on core competencies, system constraints, and clear communication.
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Think Out Loud
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