Changelog

What’s new in the AceOffer interview question catalog each month

Every month, AceOffer adds new Anthropic and OpenAI interview questions reconstructed from new candidate reports, and refreshes existing questions when new reports change the follow-up patterns or canonical answer. This page lists what shipped each month. Catalog total: 137 questions across Anthropic and OpenAI.

How the monthly refresh works

New questions — added when at least two independent candidate reports describe the same question; one report alone is held as a draft until a second confirms.
Refreshed questions— existing questions are updated when a new candidate report introduces a new follow-up, edge case, or shifts the common-mistake pattern. The question’s last-reported date moves forward; history is preserved internally.
Retired questions— if a question hasn’t been reported in 12+ months, it’s flagged as ‘cold’ on the question card but stays in the catalog for reference.
Source quality gate — reports are auto-graded by an LLM for structure and detail before they qualify; the bar is the same as for paid contributor reports.

May 2026

Refreshed (9)

OpenAI · 9

•Key-Value Store Design and Implementation
•Disease/Epidemic Spreading Simulation
•System Design: Slack
•IP Address / CIDR Iterator
•System Design: Online IDE / Sandbox Cloud IDE
•Chatbot / Bot Message Router Refactoring
•System Design: Online Chess Game
•Jetpack Compose / UI Components Implementation
•Rate Limiter Implementation

April 2026

New questions (9)

Anthropic · 3

•System Design Doc Review
•Sample-Aspect Double Descent Experiment Design
•Amusement Park / Sharing System Product Design

OpenAI · 6

•Text Editor (Buffer, Undo/Redo, Autocomplete, Collaboration)
•AI Playground System Design
•Entropy Calculation with Numerical Stability and Streaming
•Coffee Shop Ordering System Design
•Load Balancing with Multi-Tag Constraints
•FP8/BF16 Mixed Precision Training & Numerical Overflow

Refreshed (43)

Anthropic · 19

•Web Crawler
•File Deduplication
•Profiling / Stack Trace Analysis
•Inference API System Design
•Why Anthropic?
•Most Impactful Project / HM Behavioral
•Project Deep Dive / Technical Presentation
•Image Processing Pipeline
•Tokenizer Implementation
•Distributed Mode/Median
•Project Feasibility / Failure BQ
•LRU Cache
•Batch Inference System Design
•Prompt Playground System Design
•ML Model Distribution / Deployment System Design
•Recipe Manager
•Task Management System
•1-on-1 Chat System Design
•Data Batcher with Weighted Sampling

OpenAI · 24

•GPU Credit Management System
•Transformer Debugging
•System Design: Payment System
•Toy Language: Type Inference and AST
•System Design: ChatGPT / GPT Interactive Chat UI
•Classifier Training and Analysis
•Distributed Machine Count (Tree Network)
•Technical Deep Dive: Project Presentation
•ML Coding: MLP/RNN Forward/Backward Propagation
•Two-Team Turn-Based Combat System
•Behavioral: Why OpenAI / AGI Views / AI Safety
•Behavioral / Culture Fit Questions
•Social Network Follower/Followee with Temporal Queries
•Python Dependency Version Control
•NumPy Puzzle / Vectorization
•Novel Data Mining from Large Unlabeled Datasets
•System Design: Crossword Puzzle Solver Service
•System Design: URL Shortener
•Multiprocessing / Distributed Neural Network Debugging
•LLM Decoding Stopping Time / Probability Distributions
•File/Folder Deduplication and Navigation
•Dynamic Human Labeling / Task Scheduling
•System Design: Image Sharing with Deduplication
•Design Sora / Video Generation Scheduling System

March 2026

New questions (6)

Anthropic · 1

•Open-Source AI Safety / Community Benefit Discussion

OpenAI · 5

•Dynamic Human Labeling / Task Scheduling
•Multi-Shard Data Management Architecture
•Human Annotation with High-Dimensional Input
•ML Config / Configuration System
•Implement ChatGPT-like React Interface with Streaming

Refreshed (14)

Anthropic · 4

•AI Safety Culture Fit
•Culture Fit / Behavioral Questions
•Debug GRPO / RL Training Code
•Most Challenging Project (Recruiter Chat)

OpenAI · 10

•System Design: CI/CD Pipeline
•ML Search / RAG System Design
•Backpropagation
•HM Timeline / Hiring Manager Chat
•Applied Statistics and Probability
•Memory Allocator Implementation
•Behavioral: Failed Project and Impact Outside Scope
•KV Cache Implementation for Inference
•RL Bug Finding / Debugging
•Behavioral: Technical Depth / Hiring Manager Interview

February 2026

New questions (7)

Anthropic · 1

•Stream Large File to Many Machines

OpenAI · 6

•System Design: YouTube / Video Publishing Storage System
•RL Bug Finding / Debugging
•Design Sora / Video Generation Scheduling System
•Project Ambiguity and Problem-Solving
•Overlapping Key Range / Shard Rebalancing
•GPU Infrastructure and Kubernetes

Refreshed (7)

Anthropic · 2

•File Systems OA (Multi-Part)
•NumPy Debugging

OpenAI · 5

•In-Memory SQL / Database Implementation
•System Design: Webhook Delivery Service
•System Design: Place of Interest (POI) / Yelp Service
•System Design: Web Crawler
•System Design: Calendar Application

January 2026

New questions (5)

Anthropic · 2

•Task Management System
•NumPy Debugging

OpenAI · 3

•System Design: Online IDE / Sandbox Cloud IDE
•System Design: Online Chess Game
•Stock Trading System Design (Robinhood-like)

Refreshed (3)

Anthropic · 2

•In-Memory Database
•Banking System (OA)

OpenAI · 1

•Cross-Functional PM Collaboration / Culture

December 2025

New questions (5)

Anthropic · 1

•Most Challenging Project (Recruiter Chat)

OpenAI · 4

•Disease/Epidemic Spreading Simulation
•Social Network Follower/Followee with Temporal Queries
•LLM Decoding Stopping Time / Probability Distributions
•ML System Design: Image Extraction from Chat Logs for New Concepts

Refreshed (4)

Anthropic · 3

•VLIW / TPU / Kernel Optimization Assignment
•Roofline Model Analysis
•Consecutive Event / Sample Detection

OpenAI · 1

•Improve Tool / Image Recognition Model Training

November 2025

New questions (15)

Anthropic · 2

•Recipe Manager
•1-on-1 Chat System Design

OpenAI · 13

•ML Coding: MLP/RNN Forward/Backward Propagation
•NumPy Puzzle / Vectorization
•System Design: Crossword Puzzle Solver Service
•System Design: URL Shortener
•Recommendation & Search System Design
•Rate Limiter Implementation
•System Design: Image Sharing with Deduplication
•Behavioral: Technical Depth / Hiring Manager Interview
•Shortest Path in Tree Network Visiting All Task Nodes
•Game of Life
•Minimum Steps to Target Number via Modular Addition
•How Do You Measure Success in 6 Months
•ML Fundamentals (Oral)

October 2025

New questions (12)

Anthropic · 3

•Image Processing Pipeline
•Debug GRPO / RL Training Code
•Data Batcher with Weighted Sampling

OpenAI · 9

•Chatbot / Bot Message Router Refactoring
•Two-Team Turn-Based Combat System
•System Design: Calendar Application
•Jetpack Compose / UI Components Implementation
•System Design: OpenAI Platform
•Database Scaling for Notification System
•GPU Credit Scheduling System Design
•Shortest Path to Visit All Points on a Grid
•Largest Sub-Grid in 2D Array

Refreshed (1)

OpenAI · 1

•CD Directory Navigation

September 2025

New questions (8)

Anthropic · 3

•Thoughts on Anthropic as a Company / HM Discussion
•A100 Matrix Multiplication Performance Modeling
•Multi-layer Pattern Performance with Memory Constraints

OpenAI · 5

•IP Address Account Registration / Fraud Detection
•Design Functional Scalable Full-Stack Web App from Mockups
•Large Model Deployment System Design
•Behavioral: Achievements
•Behavioral: Learning from Failure

Refreshed (3)

Anthropic · 1

•GPU Cluster / Inference Infrastructure System Design

OpenAI · 2

•Behavioral: Conflict Resolution
•Behavioral: Achievements and Project Deep Dive

August 2025

New questions (4)

Anthropic · 2

•ML Model Distribution / Deployment System Design
•Consecutive Event / Sample Detection

OpenAI · 2

•System Design: Place of Interest (POI) / Yelp Service
•Binary Search / Version Search with Rate Limiting

Refreshed (1)

OpenAI · 1

•Resumable List/File Iterator

July 2025

New questions (10)

Anthropic · 4

•File Systems OA (Multi-Part)
•Career Plan / Work Preferences (Culture Fit Round)
•Attention Algorithm Implementation in PyTorch
•LLM-Based Binary Classifier Design

OpenAI · 6

•System Design: ChatGPT / GPT Interactive Chat UI
•Memory Allocator Implementation
•Behavioral / Culture Fit Questions
•File/Folder Deduplication and Navigation
•Stack Trace / Profile Stack
•Cross-Functional PM Collaboration / Culture

Refreshed (3)

Anthropic · 2

•Cloud File Storage System
•Neural Network Forward and Backward Pass Implementation

OpenAI · 1

•ML Model Debugging

June 2025

New questions (3)

Anthropic · 1

•LRU Cache

OpenAI · 2

•IP Address / CIDR Iterator
•Behavioral: Failed Project and Impact Outside Scope

May 2025

New questions (17)

Anthropic · 5

•In-Memory Database
•Project Feasibility / Failure BQ
•Batch Inference System Design
•Roofline Model Analysis
•Neural Network Forward and Backward Pass Implementation

OpenAI · 12

•System Design: Payment System
•Classifier Training and Analysis
•HM Timeline / Hiring Manager Chat
•System Design: Webhook Delivery Service
•Behavioral: Why OpenAI / AGI Views / AI Safety
•Python Dependency Version Control
•Novel Data Mining from Large Unlabeled Datasets
•KV Cache Implementation for Inference
•Improve Tool / Image Recognition Model Training
•Staff / Beat Notation Conversion
•Behavioral: Conflict Resolution
•Behavioral: Achievements and Project Deep Dive

Refreshed (1)

OpenAI · 1

•Bitwise Operations

April 2025

New questions (3)

Anthropic · 3

•Distributed Mode/Median
•Prompt Playground System Design
•VLIW / TPU / Kernel Optimization Assignment

Refreshed (1)

OpenAI · 1

•Excel Sheet Cell Dependencies and Cycle Detection

March 2025

New questions (8)

Anthropic · 6

•Why Anthropic?
•Most Impactful Project / HM Behavioral
•AI Safety Culture Fit
•Culture Fit / Behavioral Questions
•Project Deep Dive / Technical Presentation
•GPU Cluster / Inference Infrastructure System Design

OpenAI · 2

•System Design: Web Crawler
•CD Directory Navigation

Refreshed (1)

OpenAI · 1

•Track / Account Balance

February 2025

New questions (15)

Anthropic · 5

•File Deduplication
•Profiling / Stack Trace Analysis
•Inference API System Design
•Tokenizer Implementation
•Cloud File Storage System

OpenAI · 10

•System Design: CI/CD Pipeline
•GPU Credit Management System
•Transformer Debugging
•Toy Language: Type Inference and AST
•Technical Deep Dive: Project Presentation
•Backpropagation
•Applied Statistics and Probability
•Excel Sheet Cell Dependencies and Cycle Detection
•Multiprocessing / Distributed Neural Network Debugging
•Track / Account Balance

January 2025

New questions (9)

Anthropic · 1

•Web Crawler

OpenAI · 8

•Key-Value Store Design and Implementation
•System Design: Slack
•In-Memory SQL / Database Implementation
•Resumable List/File Iterator
•Distributed Machine Count (Tree Network)
•ML Search / RAG System Design
•ML Model Debugging
•Bitwise Operations

September 2024

New questions (1)

Anthropic · 1

•Banking System (OA)

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