Interview Cache
Master your next technical interview with real questions from industry leaders.
OpenAI
193 problems across 5 categories
| Done | Title | Difficulty | Updated |
|---|---|---|---|
| Implement 1NN with NumPy NewMachine Learning Engineer | Medium | May 19, 2026 | |
| Implement IP Address Arithmetic NewSoftware EngineerCoding | Hard | May 12, 2026 | |
| Design a Text-to-Video Generation System NewSoftware EngineerSystem Design | Hard | May 12, 2026 | |
| Design a Distributed Crossword Solver NewSoftware EngineerSystem Design | Hard | May 12, 2026 | |
| Simulate Infection Spread on a Grid NewMachine Learning EngineerCoding | Hard | May 11, 2026 | |
| Design a Distributed Rate Limiter NewSoftware EngineerSystem Design | Medium | May 11, 2026 | |
| Implement Social Follow Recommendations NewSoftware EngineerCoding | Medium | May 9, 2026 | |
| Design a Distributed Crossword Solver NewSoftware EngineerSystem Design | Medium | May 9, 2026 | |
| Design Mobile Model Usage Quotas NewAndroid EngineerSystem Design | Medium | May 3, 2026 | |
| Build a Compose Rating Card NewAndroid EngineerCoding | Medium | May 3, 2026 | |
| Generate Data Labeling Schedules Software EngineerCoding | Medium | Apr 28, 2026 | |
| Implement an Extensible Chatbot App Software EngineerCoding | Medium | Apr 26, 2026 | |
| Design a Slack-Like Messaging System Software EngineerSystem Design | Medium | Apr 26, 2026 | |
| Design a ChatGPT Playground Frontend EngineerSystem Design | Medium | Apr 25, 2026 | |
| Build a Streaming Chat Input Frontend EngineerCoding | Medium | Apr 25, 2026 | |
| Compute entropy and implement 1-NN Machine Learning Engineer | Medium | Apr 24, 2026 | |
| Design a Real-Time Chess Service Backend EngineerSystem Design | Medium | Apr 22, 2026 | |
| Convert IPv4 Ranges to CIDR Blocks Backend EngineerCoding | Medium | Apr 22, 2026 | |
| Implement Persistent KV Store Serialization Software EngineerCoding | Hard | Apr 20, 2026 | |
| Design a Cloud DevBox Platform Software EngineerSystem Design | Hard | Apr 20, 2026 | |
| Implement Social Graph Snapshot Queries Software EngineerCoding | Medium | Apr 13, 2026 | |
| Design a Real-Time Sensor Intelligence System Machine Learning EngineerSystem Design | Medium | Apr 13, 2026 | |
| Defend a Research Direction and Experiment Design Machine Learning Engineer | Medium | Apr 13, 2026 | |
| Design a Hosted Notebook Platform Software EngineerSystem Design | Medium | Apr 12, 2026 | |
| Design a Multi-Tenant Online IDE Software EngineerSystem Design | Medium | Apr 11, 2026 | |
| Build a File-Backed Key-Value Store Software EngineerCoding | Medium | Apr 11, 2026 | |
| Implement Chat Event Counter Software EngineerCoding | Easy | Apr 10, 2026 | |
| Search Monster Battle Strategies Machine Learning EngineerCoding | Hard | Apr 8, 2026 | |
| Schedule Incremental Labeling Tasks Machine Learning EngineerCoding | Hard | Apr 8, 2026 | |
| Implement Disease and Friend Snapshot Models Software EngineerCoding | Hard | Apr 7, 2026 | |
| Design IDE Sandbox and Payments Software EngineerSystem Design | Hard | Apr 7, 2026 | |
| Design a Distributed Crossword Solver Software EngineerSystem Design | Hard | Apr 7, 2026 | |
| Compute Infection Time in a Grid Software EngineerCoding | Hard | Apr 7, 2026 | |
| Prevent Duplicate Request Processing Software EngineerSystem Design | Hard | Apr 4, 2026 | |
| Build a Reliable Streaming Chat UI Software EngineerCoding | Hard | Apr 4, 2026 | |
| Simulate Plant Infection Spread Machine Learning EngineerCoding | Medium | Apr 3, 2026 | |
| Mine Novel Images from Unlabeled Data Machine Learning EngineerSystem Design | Medium | Apr 3, 2026 | |
| Implement Backprop for a Tiny Network Machine Learning Engineer | Hard | Apr 3, 2026 | |
| Filter Bad Human Annotations Machine Learning Engineer | Medium | Apr 3, 2026 | |
| Design Duplicate File Detection Machine Learning EngineerSystem Design | Medium | Apr 3, 2026 | |
| Design an Extensible Simulation Engine Machine Learning EngineerCoding | Hard | Apr 3, 2026 | |
| Debug MiniGPT and Backpropagate Matmul Machine Learning Engineer | Medium | Apr 3, 2026 | |
| Debug a Concurrent Job Scheduler Machine Learning EngineerCoding | Medium | Apr 3, 2026 | |
| Simulate Plant Infection With Controlled Burning Machine Learning EngineerCoding | Hard | Apr 2, 2026 | |
| Improve Training With Noisy Annotators Machine Learning Engineer | Hard | Apr 2, 2026 | |
| Design an AI playground editor Software EngineerSystem Design | Hard | Apr 2, 2026 | |
| Compute Matrix Prefix Products And Gradients Machine Learning Engineer | Hard | Apr 2, 2026 | |
| Minimize deaths in spreading plant infection Software EngineerCoding | Medium | Apr 1, 2026 | |
| Design Real-Time Collaborative Editing Machine Learning EngineerSystem Design | Medium | Mar 11, 2026 | |
| Design an Editable Text Buffer Machine Learning EngineerCoding | Medium | Mar 11, 2026 | |
| Track Expiring GPU Credits Machine Learning EngineerCoding | Medium | Mar 9, 2026 | |
| Simulate Turn-Based Monster Battles Machine Learning EngineerCoding | Medium | Mar 9, 2026 | |
| Simulate Grid Infection Machine Learning EngineerCoding | Medium | Mar 9, 2026 | |
| Infer Generic Return Types Machine Learning EngineerCoding | Medium | Mar 9, 2026 | |
| Find Minimum Compatible Version Machine Learning EngineerCoding | Medium | Mar 9, 2026 | |
| Debug a Broken Transformer Machine Learning Engineer | Medium | Mar 3, 2026 | |
| Rebalance shard ranges under overlap limit Software EngineerCoding | Medium | Mar 1, 2026 | |
| Implement follow graph with snapshots Software EngineerCoding | Hard | Mar 1, 2026 | |
| Design a payment system with holds and batching Software EngineerSystem Design | Hard | Mar 1, 2026 | |
| Implement Time-Aware GPU Credit Ledger Software EngineerCoding | Medium | Feb 23, 2026 | |
| Design a GPU-Efficient Video Service Software EngineerSystem Design | Medium | Feb 23, 2026 | |
| Model particle hits on a screen Software EngineerCoding | Hard | Feb 22, 2026 | |
| Design a Slack-like real-time messaging system Software EngineerSystem Design | Hard | Feb 12, 2026 | |
| Improve classifier with noisy multi-annotator labels Machine Learning Engineer | Hard | Feb 11, 2026 | |
| Implement type AST and infer generics Software EngineerCoding | Hard | Feb 11, 2026 | |
| Design a crossword puzzle solver system Software EngineerSystem Design | Hard | Feb 11, 2026 | |
| Analyze matrix multiplication complexity Machine Learning EngineerCoding | Hard | Feb 11, 2026 | |
| Design a sandboxed cloud IDE Software EngineerSystem Design | Easy | Jan 22, 2026 | |
| Answer project deep dive and cross-functional questions Software EngineerBehavioral | Easy | Jan 22, 2026 | |
| Design a distributed crossword fill solver Software EngineerSystem Design | Medium | Jan 17, 2026 | |
| Implement a memory allocator with malloc/free Software EngineerCoding | Medium | Jan 9, 2026 | |
| How would you build an image classifier with dirty data? Machine Learning EngineerSystem Design | Easy | Jan 6, 2026 | |
| Explain KV cache in Transformer inference Machine Learning EngineerCoding | Medium | Jan 6, 2026 | |
| Design a RAG system with evaluation Machine Learning EngineerSystem Design | Medium | Jan 6, 2026 | |
| Refactor a chat message processing function Software EngineerCoding | Hard | Jan 2, 2026 | |
| Design a ChatGPT-like web chat UI Software EngineerSystem Design | Hard | Jan 2, 2026 | |
| Select high-quality math documents from crawls Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Implement credit ledger with out-of-order timestamps Software EngineerCoding | Hard | Dec 15, 2025 | |
| Implement an in-memory SQL-like table Software EngineerCoding | Hard | Dec 15, 2025 | |
| Explain what torch.distributed.barrier does Machine Learning EngineerCoding | Hard | Dec 15, 2025 | |
| Design and optimize a RAG system Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design an image/video near-duplicate detection system Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design an AWS fine-tuning platform for LLMs Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a search query autocomplete system Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a Retrieval-Augmented Generation (RAG) system Software EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a regional surge pricing strategy Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a recommendation system end-to-end Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a payment processing system Software EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a harmful video content moderation system Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a CI/CD system with stuck-job handling Software EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a CI/CD system with live log streaming Software EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design a chatbot fallback for unknown questions Machine Learning EngineerSystem Design | Hard | Dec 15, 2025 | |
| Design an OOD detection system Machine Learning EngineerSystem Design | Medium | Dec 14, 2025 | |
| Explain your perspective on AI safety Software EngineerBehavioral | Hard | Dec 8, 2025 | |
| Design a URL shortening service Software EngineerSystem Design | Hard | Dec 8, 2025 | |
| Design an enterprise RAG assistant for internal docs Software EngineerSystem Design | Hard | Dec 7, 2025 | |
| Explain JS threading and useState vs useRef Software EngineerCoding | Hard | Dec 6, 2025 | |
| Design reliable high-volume chatbot system Software EngineerSystem Design | Hard | Dec 6, 2025 | |
| Implement map serialization and deserialization Software EngineerCoding | Medium | Dec 1, 2025 | |
| Discuss views on AI safety and its impacts Software EngineerBehavioral | Medium | Dec 1, 2025 | |
| Design Slack-like multi-tenant global messaging system Software EngineerSystem Design | Medium | Dec 1, 2025 | |
| Implement a persistent sharded key-value store Software EngineerCoding | Hard | Nov 24, 2025 | |
| Design a social network with snapshots Software EngineerCoding | Medium | Nov 16, 2025 | |
| Implement IPv4 iterators and CIDR expansion Software EngineerCoding | Medium | Nov 15, 2025 | |
| Implement toy-language types and generic substitution Software EngineerCoding | Medium | Nov 13, 2025 | |
| Design a multi-device calendar application Software EngineerSystem Design | Medium | Nov 9, 2025 | |
| Simulate turn-based monster team battle Software EngineerCoding | Medium | Oct 30, 2025 | |
| Compute time to infect all cells Machine Learning EngineerCoding | Hard | Oct 24, 2025 | |
| Explain motivation and mission alignment Machine Learning EngineerBehavioral | Hard | Oct 20, 2025 | |
| Design a distributed crossword solving service Software EngineerSystem Design | Hard | Oct 17, 2025 | |
| Debug and harden trial-assignment Python code Data Scientist | Medium | Oct 13, 2025 | |
| Write SQL for post-trial conversion cohorts Data Scientist | Medium | Oct 13, 2025 | |
| Design and analyze a free-trial A/B test Data ScientistProduct Sense | Hard | Oct 13, 2025 | |
| Debug and fix a PyTorch Transformer training loop Data Scientist | Hard | Oct 13, 2025 | |
| Evaluate a free-trial A/B test Data ScientistProduct Sense | Easy | Oct 4, 2025 | |
| Compute signup rate and retention from raw logs Data Scientist | Easy | Oct 4, 2025 | |
| Train a classifier and analyze dataset Machine Learning Engineer | Hard | Sep 6, 2025 | |
| Parse and build binary data in Python Software Engineer | Medium | Sep 6, 2025 | |
| Optimize C++ Performance with Provided Concurrency Software EngineerCoding | Medium | Sep 6, 2025 | |
| Implement KV store serialization Software EngineerCoding | Medium | Sep 6, 2025 | |
| Implement KV store and plan type conversions Software EngineerCoding | Medium | Sep 6, 2025 | |
| Implement expiring credit ledger Software EngineerCoding | Medium | Sep 6, 2025 | |
| Implement compile-time function type verification Software EngineerCoding | Medium | Sep 6, 2025 | |
| Implement and Debug Backprop in NumPy Software Engineer | Medium | Sep 6, 2025 | |
| Implement an expiring GPU-credit manager Software EngineerCoding | Medium | Sep 6, 2025 | |
| Implement a Simulated Memory Allocator Software EngineerCoding | Medium | Sep 6, 2025 | |
| Find earliest supporting version under constraints Machine Learning EngineerCoding | Medium | Sep 6, 2025 | |
| Design multi-tenant CI/CD platform Software EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design credit balance with vector-clock expirations Software EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design an online ads serving system Software EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design an ML search system Machine Learning EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design an enterprise RAG system Machine Learning EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design an AI chatbot with browser storage Software EngineerSystem Design | Medium | Sep 6, 2025 | |
| Design a persistent key-value store Software EngineerCoding | Medium | Sep 6, 2025 | |
| Design a parser for a hypothetical language Software EngineerCoding | Medium | Sep 6, 2025 | |
| Design a multi-tenant Slack-like messenger Software EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design a GPT chat UI with snapshots and sharing Software EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design a CI/CD pipeline Software EngineerSystem Design | Hard | Sep 6, 2025 | |
| Design a CI/CD pipeline Software EngineerSystem Design | Hard | Sep 6, 2025 | |
| Debug a transformer training pipeline Machine Learning Engineer | Hard | Sep 6, 2025 | |
| Design a GPU credit system and scheduler Software EngineerSystem Design | Hard | Aug 13, 2025 | |
| Design a CI/CD pipeline with scheduler Software EngineerSystem Design | Hard | Aug 13, 2025 | |
| Implement vectorized NumPy ops and explain broadcasting Machine Learning Engineer | Medium | Aug 11, 2025 | |
| Diagnose Transformer training and inference bugs Machine Learning Engineer | Hard | Aug 11, 2025 | |
| Design a production RAG system Machine Learning EngineerSystem Design | Hard | Aug 11, 2025 | |
| Derive MLE and Bayesian posterior for Bernoulli Machine Learning Engineer | Medium | Aug 11, 2025 | |
| Implement in-memory KV store with serialization Software EngineerCoding | Medium | Aug 8, 2025 | |
| Implement a GPU credit manager Software EngineerCoding | Medium | Aug 8, 2025 | |
| Design multi-tenant CI/CD workflow system Software EngineerSystem Design | Hard | Aug 8, 2025 | |
| Design a multi-tenant CI/CD platform Software EngineerSystem Design | Hard | Aug 8, 2025 | |
| Merge overlapping intervals Software EngineerCoding | Medium | Aug 4, 2025 | |
| Manage GPU Credits with Expiration Software EngineerCoding | Medium | Aug 4, 2025 | |
| Implement persistent key-value store Software EngineerCoding | Medium | Aug 4, 2025 | |
| Find earliest supporting dependency version Machine Learning EngineerCoding | Medium | Aug 4, 2025 | |
| Design GPU credit allocator Software EngineerSystem Design | Hard | Aug 4, 2025 | |
| Design enterprise RAG search system Machine Learning EngineerSystem Design | Hard | Aug 4, 2025 | |
| Design an in-memory database Software EngineerSystem Design | Hard | Aug 4, 2025 | |
| Design an End-to-End ML System Software EngineerSystem Design | Hard | Aug 4, 2025 | |
| Design AI chat bot system Software EngineerSystem Design | Medium | Aug 4, 2025 | |
| Design a CI/CD Pipeline Software EngineerSystem Design | Hard | Aug 4, 2025 | |
| Debug transformer and train classifier Machine Learning Engineer | Hard | Aug 4, 2025 | |
| Debug a Machine Learning Pipeline Software Engineer | Medium | Aug 4, 2025 | |
| Identify Bugs in Python Script for User Assignment Data ScientistCoding | Medium | Aug 4, 2025 | |
| Determine Metrics to Measure Free-Trial Impact on Subscriptions Data ScientistProduct Sense | Medium | Aug 4, 2025 | |
| Design Schema for Accurate Subscription State Tracking Data Scientist | Medium | Aug 4, 2025 | |
| Train and analyze a classifier Machine Learning Engineer | Medium | Jul 31, 2025 | |
| Merge overlapping time intervals efficiently Software EngineerCoding | Medium | Jul 31, 2025 | |
| Design an in-memory key-value database Software EngineerSystem Design | Hard | Jul 31, 2025 | |
| Design an enterprise RAG system Machine Learning EngineerSystem Design | Hard | Jul 31, 2025 | |
| Design a GPU credit allocation service Software EngineerSystem Design | Hard | Jul 31, 2025 | |
| Debug a transformer training pipeline Machine Learning Engineer | Hard | Jul 31, 2025 | |
| Implement in-memory DB querying Software EngineerCoding | Medium | Jul 29, 2025 | |
| Design in-memory database API Software EngineerSystem Design | Medium | Jul 29, 2025 | |
| Design a response-ranking ML system Software EngineerSystem Design | Hard | Jul 28, 2025 | |
| Debug a failing ML classifier Software Engineer | Hard | Jul 28, 2025 | |
| Implement node messaging and path discovery Software EngineerCoding | Medium | Jul 27, 2025 | |
| Implement an expiring GPU credits ledger Software EngineerCoding | Medium | Jul 27, 2025 | |
| Design ChatGPT homepage with streaming choices Software EngineerSystem Design | Hard | Jul 27, 2025 | |
| Design a low-latency RAG system Machine Learning EngineerSystem Design | Hard | Jul 27, 2025 | |
| Design a fullstack app with frontend focus Software EngineerSystem Design | Hard | Jul 27, 2025 | |
| Describe handling pressure and present your work Machine Learning EngineerBehavioral | Medium | Jul 27, 2025 | |
| Build and troubleshoot image classification and backprop Machine Learning Engineer | Hard | Jul 27, 2025 | |
| Implement a serializable key-value store Software EngineerCoding | Medium | Jul 15, 2025 | |
| Design an ML search system with RAG Machine Learning EngineerSystem Design | Hard | Jul 15, 2025 | |
| Design an in-memory database Machine Learning EngineerSystem Design | Hard | Jul 15, 2025 | |
| Design a scalable payment processor Software EngineerSystem Design | Hard | Jul 15, 2025 | |
| Design Schema and Logic for Subscription Event Tracking Data Scientist | Medium | Jul 12, 2025 | |
| Analyze A/B Test Results for Subscription Conversion Rates Data ScientistProduct Sense | Medium | Jul 12, 2025 | |
| Design webhook, POI, chat, CI/CD, payments Software EngineerSystem Design | Medium | Jul 4, 2025 | |
| Implement in-memory database insert and delete operations Machine Learning EngineerCoding | Hard | Apr 6, 2025 | |
| Design LLM search handling long token inputs Machine Learning EngineerSystem Design | Hard | Apr 6, 2025 | |
| Implement IPv4 and CIDR iterators Software EngineerCoding | Medium | Jan 10, 2025 | |
| Design an online real-time chess game Software EngineerSystem Design | Medium | Jan 10, 2025 |