Real Coding & ML Interview Questions

3,680 reported questions, newest reports first. Browse by company or by topic.

• Classifier Analysis
  OpenAIML Fundamentals & AlgorithmsDifficulty 3/5Last asked Nov 7, 2025
• Two-Team Turn-Based Battle Simulator
  OpenAICoding QuestionsDifficulty 3/5Last asked Jun 29, 2026
• Clean Noisy Human Labels by Scoring Annotator Reliability
  OpenAIML Fundamentals & AlgorithmsDifficulty 3/5Last asked Oct 28, 2026
• Backward Pass of a Row-Sharded MLP with all_gather
  OpenAIDeep Learning & ArchitecturesDifficulty 4/5Last asked Aug 9, 2026
• Debug a Mini GPT and Add a KV Cache
  OpenAIDeep Learning & ArchitecturesDifficulty 4/5Last asked Jun 9, 2026
• LLM conceptual questions
  OpenAIAmazonAppleResearch & Paper UnderstandingDifficulty 3/5Last asked Jun 29, 2026
• Toy Language Type System
  OpenAICoding QuestionsDifficulty 3/5Last asked May 26, 2026
• Grid Infection and Immunity Simulation
  OpenAICoding QuestionsDifficulty 4/5Last asked Jun 29, 2026
• Earliest Supporting Version with a Probe Budget
  OpenAICoding QuestionsDifficulty 3/5Last asked May 8, 2026
• Time-Based Key-Value Store
  OpenAICoding QuestionsDifficulty 3/5Last asked Oct 19, 2025
• Applied Stats: Distributed Averaging Under Noisy Communication
  OpenAIML Fundamentals & AlgorithmsDifficulty 4/5Last asked Dec 15, 2025
• Resumable Iterators
  OpenAICoding QuestionsDifficulty 4/5Last asked Aug 17, 2025
• Binary Classifier from Next-Token Probabilities
  AnthropicLLMs & Prompt EngineeringDifficulty 3/5Last asked Nov 11, 2025
• ML Debugging (Transformer)
  OpenAIDeep Learning & ArchitecturesDifficulty 4/5Last asked Mar 20, 2026
• Count and Map a Machine Tree by Message Passing
  OpenAICoding QuestionsDifficulty 3/5Last asked Nov 16, 2025
• IPv4 Iterators and CIDR Blocks
  OpenAICoding QuestionsDifficulty 3/5Last asked Nov 15, 2025
• Mine Training Data from Noisy UI Interaction Logs
  OpenAISystem Design for MLDifficulty 4/5Last asked Nov 2, 2025
• Chatbot Code Refactoring
  OpenAISystem Design for MLDifficulty 3/5Last asked Nov 13, 2025
• Simulating Particle Hits on an Infinite Screen
  OpenAIML Fundamentals & AlgorithmsDifficulty 3/5Last asked Mar 23, 2026
• Bias-Variance Trade-off in Classification
  Citadel SecuritiesML Fundamentals & AlgorithmsDifficulty 3/5Last asked Jul 14, 2025
• Classify a Float Into One of Two Arrays
  Google DeepMindML Fundamentals & AlgorithmsDifficulty 3/5Last asked Dec 8, 2025
• Implement a Two-Hidden-Layer MLP with Backpropagation in NumPy
  AppleMetaScale AIDeep Learning & ArchitecturesDifficulty 3/5Last asked Jul 13, 2025
• Resumable Iterator
  OpenAICoding QuestionsDifficulty 3/5Last asked Jul 12, 2025
• Social Network with Immutable Snapshots + Followers Index + Recommendations
  OpenAICoding QuestionsDifficulty 3/5Last asked Jun 28, 2026
• Compute Softmax Entropy with Constant Extra Space
  OpenAIML Fundamentals & AlgorithmsDifficulty 3/5Last asked Jun 3, 2026
• Designing a Harmful Content Detection System
  TikTokSystem Design for MLDifficulty 4/5Last asked Jul 12, 2025
• Transformer Block with a Manual Backward Pass
  TeslaDeep Learning & ArchitecturesDifficulty 4/5Last asked Aug 11, 2025
• ML + CS Fundamentals (2)
  Google DeepMindML Fundamentals & AlgorithmsDifficulty 3/5Last asked Dec 8, 2025
• ML + CS Fundamentals (1)
  Google DeepMindML Fundamentals & AlgorithmsDifficulty 3/5Last asked Dec 8, 2025
• Design Prompt Playground
  AnthropicSystem Design for MLDifficulty 3/5Last asked Oct 13, 2026
• Compare PPO, DPO, and GRPO
  AppleAmazonReinforcement LearningDifficulty 4/5Last asked Jul 13, 2025
• CI/CD Job Scheduler Design using Kubernetes and Docker
  OpenAISystem Design for MLDifficulty 4/5Last asked Jun 11, 2026
• Dynamic Batch Inference
  xAILLMs & Prompt EngineeringDifficulty 3/5Last asked Dec 28, 2025
• Crossword Puzzle Solver
  OpenAISystem Design for MLDifficulty 4/5Last asked Jan 5, 2026
• Print a Matrix in Diagonal Order
  Google DeepMindCoding QuestionsDifficulty 2/5Last asked Dec 8, 2025
• Generate a Random Number Given Probability Distribution
  Google DeepMindCoding QuestionsDifficulty 3/5Last asked Dec 8, 2025
• Distributed Machine Cluster Count
  OpenAICoding QuestionsDifficulty 3/5Last asked Jun 19, 2026
• Balanced Tag-Pair Sequence
  OpenAICoding QuestionsDifficulty 2/5Last asked Apr 19, 2026
• K-Means Clustering on Image Patches
  TeslaDeep Learning & ArchitecturesDifficulty 3/5Last asked Jul 12, 2025
• GPU Credit Ledger with Expiring Grants
  OpenAICoding QuestionsDifficulty 3/5Last asked Jul 21, 2026
• Parallel Batch Image Transformation Pipeline
  AnthropicML Fundamentals & AlgorithmsDifficulty 3/5Last asked Jun 26, 2026
• Streaming Entropy (Numerical Stability + Online Accumulation)
  OpenAICoding QuestionsDifficulty 3/5Last asked Jun 22, 2026
• Disagreeing With a Technical Decision
  AnthropicResearch & Paper UnderstandingDifficulty 3/5Last asked Jun 26, 2026
• Design a GPU Scheduling Platform
  OpenAIAnthropicSystem Design for MLDifficulty 4/5Last asked Jun 30, 2026
• Implement a Vision Transformer (ViT) from Scratch
  Applied IntuitionAppleDeep Learning & ArchitecturesDifficulty 3/5Last asked Nov 2, 2025
• Autograd / Manual Backprop + Hillis-Steele Scan
  OpenAICoding QuestionsDifficulty 3/5Last asked May 31, 2026
• Recover x from a Monotonic Function Output
  Google DeepMindCoding QuestionsDifficulty 3/5Last asked Dec 8, 2025
• Dot Product with Run-Length Encoded Vectors
  MetaCoding QuestionsDifficulty 3/5Last asked Jul 13, 2025
• NumPy Puzzle: 1-NN Vectorization → Wx+b Network
  OpenAICoding QuestionsDifficulty 3/5Last asked May 20, 2026
• Async Comparator for Answer Ranking
  xAILLMs & Prompt EngineeringDifficulty 3/5Last asked Jul 14, 2025
• In-Memory Rate Limiter
  OpenAICoding QuestionsDifficulty 3/5Last asked Apr 22, 2026
• Maximum of a Bitonic Array
  Google DeepMindCoding QuestionsDifficulty 3/5Last asked Nov 15, 2025
• Prompt sampling
  Reflection AIML Fundamentals & AlgorithmsDifficulty 3/5Last asked Jul 3, 2026
• Math Reasoning: Stopping Time / Las Vegas Algorithm
  OpenAICoding QuestionsDifficulty 4/5Last asked May 31, 2026
• LLM Fundamentals: Quantization, FlashAttention, Parallelism
  CitadelMLOps & DeploymentDifficulty 3/5Last asked Jan 8, 2026
• Agents / Coding with LLMs
  AnthropicLLMs & Prompt EngineeringDifficulty 4/5Last asked Jun 29, 2026
• Sample from a Gaussian Distribution Using Only Uniform Sampling
  AppleML Fundamentals & AlgorithmsDifficulty 2/5Last asked Jul 11, 2025
• Implement Beam Search for Language Model Decoding
  NVIDIALLMs & Prompt EngineeringDifficulty 3/5Last asked Jul 12, 2025
• Implement a Unix-like `cd` Command (with Symlink Follow-up)
  OpenAICoding QuestionsDifficulty 4/5Last asked Dec 27, 2025
• CAP Theorem in Distributed Systems
  Google DeepMind1XSystem Design for MLDifficulty 3/5Last asked Dec 8, 2025
• Design ChatGPT: A Conversational LLM Serving Platform
  OpenAIAnthropicxAISystem Design for MLDifficulty 4/5Last asked Jul 21, 2026
• Probability of Staying Dry with One Umbrella
  Citadel SecuritiesML Fundamentals & AlgorithmsDifficulty 3/5Last asked Jul 14, 2025
• Crash-Resilient LRU Memoization Cache
  AnthropicCoding QuestionsDifficulty 3/5Last asked Oct 13, 2026
• Data Labeling Task Scheduler
  OpenAICoding QuestionsDifficulty 3/5Last asked May 31, 2026
• System Design: Chess Game
  OpenAISystem Design for MLDifficulty 3/5Last asked Jun 26, 2026
• Implement an in-memory TTL cache (optionally LRU)
  OpenAICoding QuestionsDifficulty 3/5Last asked Apr 22, 2026
• Efficient Tokenizer
  PerplexityLLMs & Prompt EngineeringDifficulty 4/5Last asked Jan 6, 2026
• Deduplicate Files
  AnthropicCoding QuestionsDifficulty 3/5Last asked Jun 23, 2026
• Code Reading — 400-line PyTorch Refactor
  OpenAICoding QuestionsDifficulty 3/5Last asked Mar 9, 2026
• DNA Fragment Chain Reconstruction
  Microsoft AICoding QuestionsDifficulty 3/5Last asked Nov 24, 2025
• Implement Masked Cross Entropy Loss with Label Smoothing
  OpenAIML Fundamentals & AlgorithmsDifficulty 3/5
• LLM Questions: Training Systems, Hardware, and Scaling
  CitadelMLOps & DeploymentDifficulty 3/5Last asked Jan 8, 2026
• Design a Hosted ML Notebook Platform
  OpenAISystem Design for MLDifficulty 4/5Last asked Feb 1, 2026
• Convert Stack Samples to Trace Events
  AnthropicCoding QuestionsDifficulty 3/5Last asked Jun 17, 2026
• Web Crawler with URL Normalization
  AnthropicCoding QuestionsDifficulty 3/5Last asked May 3, 2026
• In-Memory Banking System
  AnthropicCoding QuestionsDifficulty 4/5Last asked Jun 15, 2026
• Simulate the cd Command
  OpenAICoding QuestionsDifficulty 3/5Last asked Apr 19, 2026
• ModalLock and FairModalLock
  OpenAICoding QuestionsDifficulty 4/5Last asked Mar 30, 2026
• Distributed Device Control
  OpenAISystem Design for MLDifficulty 4/5Last asked Aug 19, 2026
• Combining Disjoint OLS Regressions and Efficiently Updating the Model with New Variables
  AquaticML Fundamentals & AlgorithmsDifficulty 4/5Last asked Nov 2, 2025
• MDP Value Iteration and Policy Iteration
  TeslaReinforcement LearningDifficulty 3/5Last asked Nov 2, 2025
• Design a GPU Inference Serving System
  AnthropicNVIDIASystem Design for MLDifficulty 4/5Last asked Jun 21, 2026
• Layer Normalization
  TikTokML Fundamentals & AlgorithmsDifficulty 3/5Last asked Dec 3, 2025
• Implement Inference with Probability Using NumPy
  OpenAICoding QuestionsDifficulty 3/5
• Walk Me Through Your Most Technically Complex Project
  AnthropicML Fundamentals & AlgorithmsDifficulty 3/5Last asked Jun 23, 2026
• Design Model Weight Distribution
  AnthropicSystem Design for MLDifficulty 3/5Last asked Jun 17, 2026
• In-memory database
  AnthropicCoding QuestionsDifficulty 3/5Last asked May 10, 2026
• Count Lakes Wrapped by a Given Island
  MetaCoding QuestionsDifficulty 3/5Last asked Jul 13, 2025
• Reproduce Double Descent in Linear Regression
  OpenAIML Fundamentals & AlgorithmsDifficulty 3/5
• Compute the Distribution of LLM Decoding Stopping Time and Build a Strategy Against Adversaries
  OpenAILLMs & Prompt EngineeringDifficulty 4/5
• Find the Incorrect Data Labeler
  OpenAICoding QuestionsDifficulty 3/5
• Cloud Storage System
  AnthropicCoding QuestionsDifficulty 3/5Last asked Mar 29, 2026
• Design a Distributed Training Platform for Foundation Models
  OpenAISystem Design for MLDifficulty 4/5Last asked Jun 30, 2026
• Best Time to Buy and Sell Stock with at Most k Transactions
  OptiverCoding QuestionsDifficulty 4/5Last asked Aug 5, 2025
• Implement and Debug a Minimal Neural Network Training Loop (PyTorch)
  OpenAICoding QuestionsDifficulty 3/5
• Streaming GPU Task Scheduler and Idle Interval Query
  Fireworks AIMLOps & DeploymentDifficulty 3/5Last asked Jun 19, 2026
• Game of Life
  xAICoding QuestionsDifficulty 3/5Last asked Mar 29, 2026
• REST API Integration and Aggregation
  StripeCoding QuestionsDifficulty 3/5Last asked Jun 30, 2026
• Implement a Nested Tic-Tac-Toe Game Engine
  GoogleCoding QuestionsDifficulty 3/5Last asked Dec 4, 2025
• Design a Grounded AI Chatbot App
  OpenAISystem Design for MLDifficulty 4/5Last asked Mar 22, 2026
• Minimum Remove to Make Valid Parentheses
  MetaCoding QuestionsDifficulty 3/5Last asked Aug 10, 2025
• Memory Allocator
  OpenAICoding QuestionsDifficulty 4/5Last asked Jun 11, 2026
• Design a Distributed AI Model Downloader
  AnthropicSystem Design for MLDifficulty 4/5Last asked Jun 30, 2026
• Shortest Item-to-Item Travel Distance Across Pins
  PinterestCoding QuestionsDifficulty 3/5Last asked Nov 20, 2025
• ML Take-Home: 4-Hour Experiment plus Live Review
  AnthropicResearch & Paper UnderstandingDifficulty 4/5Last asked Apr 28, 2026
• Shard Rebalance / Overlapping Key Range
  OpenAICoding QuestionsDifficulty 3/5Last asked Jun 26, 2026
• Cell Simulation / Conway’s Game of Life
  OpenAICoding QuestionsDifficulty 3/5
• Message Event Aggregation in a 5-Minute Sliding Window
  OpenAICoding QuestionsDifficulty 3/5Last asked Oct 26, 2026
• Durable Key-Value Store Serialization
  OpenAICoding QuestionsDifficulty 3/5Last asked Oct 13, 2026
• ML Fundamentals Deep Dive (AI/ML & MLE Roles)
  GoogleML Fundamentals & AlgorithmsDifficulty 4/5Last asked Jun 26, 2026
• In-Memory Database with SQL Operations
  OpenAICoding QuestionsDifficulty 3/5Last asked Nov 7, 2025
• Time-Aware Social Network Follow Graph with Recommendations
  OpenAICoding QuestionsDifficulty 4/5
• Implement an in-memory key-value store with time-travel (versioned snapshots)
  OpenAICoding QuestionsDifficulty 4/5
• OpenSheet: Spreadsheet with Cell Dependencies
  OpenAICoding QuestionsDifficulty 3/5Last asked Nov 21, 2025
• IP Address / CIDR Iterator
  OpenAICoding QuestionsDifficulty 3/5Last asked May 15, 2026
• LLM with Beam Search and Nucleus Sampling (Meta MSL)
  MetaLLMs & Prompt EngineeringDifficulty 4/5Last asked Apr 11, 2026
• ML Fundamentals and Model Debugging Rapid-Fire
  AppleML Fundamentals & AlgorithmsDifficulty 3/5Last asked Jun 10, 2026
• K-th Element on a Streaming Time Window
  xAICoding QuestionsDifficulty 3/5Last asked Jan 14, 2026
• Distributed Matrix Multiplication — DP and FSDP
  xAICoding QuestionsDifficulty 4/5Last asked Apr 4, 2026
• Design an AI Prompt Playground
  AnthropicSystem Design for MLDifficulty 4/5Last asked Jun 26, 2026