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Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
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- 546
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- 11
- Topics
- 8
- Languages
Showing 6421–6450 of 9403 results
- OpenAIHardSoftware EngineerReason About Binary Search with One-Call-Delayed Feedback
Implement and analyze binary search under a 1-step delayed-feedback protocol where each query response evaluates the previous guess.
Software Engineering FundamentalsTechnical Screenbinary-searchinteractivealgorithms - OpenAIMediumSoftware EngineerRebalance shard ranges under overlap limit
This problem tests interval manipulation and greedy optimization by requiring you to adjust a set of shard ranges so that no more than k ranges overlap at any integer point, while minimizing the number of boundaries moved.
Coding & AlgorithmsTechnical ScreenAlgorithmsSweep-LineIntervals - OpenAIMediumSoftware EngineerRecruiter Screen: Current Work, What You Want Next, Level and Work Authorization
Prepare for a recruiter screen for a software engineering role that asks what you are working on now, what you want next along with your current level and promotion history, and your work authorization. Tests concise, concrete answers that give a recruiter what they need to move a candidate forward.
Behavioral & LeadershipHR Screen - OpenAIMediumSoftware EngineerRefactor a Chatbot into Clean Object-Oriented Components
Tests object-oriented design and refactoring skills by decoupling a monolithic chatbot script into modular, testable, and extensible components adhering to SOLID principles.
Software Engineering FundamentalsTechnical ScreenObject-Oriented DesignRefactoringDesign Patterns - OpenAIHardSoftware EngineerRefactor a chat message processing function
This problem tests your ability to refactor procedural, error-prone code into a robust, extensible pipeline for parsing and managing chat message state.
Coding & AlgorithmsTechnical ScreenRefactoringString-ManipulationOOP - OpenAIHardMachine Learning EngineerRepair a Broken Tiny Language Model, Then Make Decoding Incremental
Find four planted bugs in a compact PyTorch decoder-only language model (some produce NaNs, some silently ruin learning), then add key/value caching so generation processes one new token per step.
Machine LearningOnsitepytorchtransformersdebugging - OpenAIHardSoftware EngineerResolve Short-Link Redirect Chains That May Loop
Follow single-target redirects from a start code and return the final code, or the last code before the walk would revisit one. Then answer many starts in linear total time. Tests visited-set bookkeeping and functional-graph structure.
Coding & AlgorithmsTechnical Screengraphsfunctional-graphcycle-detection - OpenAIMediumSoftware EngineerReturn the Lexicographically Smallest Topological Order
Implement a deterministic topological sort using a min-heap to return the lexicographically smallest ordering of a directed graph, or detect cycles and return an empty list.
Coding & AlgorithmsOnsitegraphtopological-sortheap - OpenAIHardSoftware EngineerRotate Couriers Daily at Minimum Total Cost
Choose one courier company per day so that no company works two days in a row and the total price is minimal, then return the schedule. Tests DP over a small state, path reconstruction, and the best/second-best trick for k options.
Coding & AlgorithmsTechnical Screendynamic-programmingreconstructionarrays - OpenAIHardMachine Learning EngineerSchedule Incremental Labeling Tasks
This problem tests the ability to design an incremental task scheduler that balances workload across a pool of annotators while maintaining fairness and deterministic state transitions.
Coding & AlgorithmsOnsiteHeapsSchedulingGreedy - OpenAIHardMachine Learning EngineerSearch Monster Battle Strategies
Design a search algorithm using state-space exploration to find the minimum number of turns required to defeat a boss given transient health, scripted boss attacks, and a single-use revive.
Coding & AlgorithmsOnsiteBreadth-First SearchState Space SearchGraph Algorithms - OpenAIHardMachine Learning EngineerSelect high-quality math documents from crawls
This question assesses the ability to design a scalable pipeline that ingests, cleans, extracts, and filters high-quality mathematical content from diverse, noisy web-crawled sources.
ML System DesignOnsiteSystem DesignNLPData Engineering - OpenAIMediumSoftware EngineerSerialize and Restore an In-Memory Key-Value Store
Design and implement a deterministic binary serializer and strict deserializer for a string key-value store, ensuring robust input validation against corruption, truncation, duplicate keys, and trailing data.
Software Engineering FundamentalsTechnical Screenbinary-serializationsystemsdata-encoding - OpenAIHardMachine Learning EngineerSimulate Infection Spread on a Grid
Implement a discrete-time cellular automaton simulating epidemic spread on a 2D grid with multi-day infection states, immunity waning, and mortality rules.
Coding & AlgorithmsTechnical ScreenSimulationMatrixCellular Automata - OpenAIMediumMachine Learning EngineerSimulate Infection Spread with Immunity and Recovery
Implement a cellular automaton simulation modeling disease spread on a 2D grid with discrete cell states and timed recovery.
Coding & AlgorithmsTechnical ScreenGrid SimulationCellular AutomataBFS - OpenAIHardMachine Learning EngineerSimulate Plant Infection With Controlled Burning
This question evaluates a candidate's ability to implement discrete-time grid simulations with delayed state transitions, reason about simultaneous updates and neighborhood effects, and perform a limited combinatorial optimization (choosing one row or column) to minimize a global outcome.
Coding & AlgorithmsOnsite - OpenAIMediumMachine Learning EngineerSimulate Turn-Based Monster Battles
This problem tests your ability to design a stateful simulation engine that handles turn-based mechanics, complex status modifiers, and dynamic combat interactions.
Coding & AlgorithmsOnsiteSimulationState ManagementGame Logic - OpenAIEasySoftware EngineerSimulate a Turn-Based Two-Player Game
This problem tests your ability to design a robust state management system and implement validation logic for a rule-based game.
Coding & AlgorithmsTechnical ScreenState ManagementAPI DesignSimulation - OpenAIMediumSoftware EngineerSliding-Window Chat Analytics: Recent Counts, Live Sessions, Out-of-Order Events
A three-part coding exercise: build an in-memory chat analytics service that counts each chat's interactions in a closed 15-minute sliding window, tracks each user's live sessions from touch and close events, and stays correct when events arrive out of order. It tests bounded-memory eviction, efficient updates and queries, and exact window and ordering semantics.
Software Engineering FundamentalsOnsite - OpenAIMediumSoftware EngineerSliding-Window Forklift Telemetry: Pings, Shifts, Late Events
Build an in-memory telemetry service that counts a forklift's recent pings in a 15-minute window, tracks which forklifts are currently on an active shift, and stays correct when pings arrive late and out of order. Tests bounded-memory eviction and exact window semantics.
Software Engineering FundamentalsOnsitesliding-windowstreamingdata-structures - OpenAIMediumSoftware EngineerSocial Graph with Follow/Unfollow, Snapshots, History Queries and Recommendations
A software engineer phone-screen coding problem: build an in-memory social graph that supports follow and unfollow, point-in-time snapshots, queries of who followed whom as of an earlier snapshot, and recommendations of users to follow. It tests data-structure choice, versioned history, and deterministic ranking.
Software Engineering FundamentalsTechnical Screen - OpenAIMediumSoftware EngineerSpreading Contagion on a Grid
Tests modeling multi-source breadth-first search (BFS) on a 2D grid to compute simultaneous state propagation across discrete time steps.
Coding & AlgorithmsTechnical Screenmulti-source-bfsgraphsmatrix - OpenAIMediumSoftware EngineerSpreadsheet engine with setCell/getCell, cell references, and cycle detection
Build a small spreadsheet engine with setCell and getCell, where formulas reference other cells and a write that would create a circular dependency must be detected. The exercise also asks for live unit tests, probing data modeling, dependency graphs, cache invalidation and test design.
Software Engineering FundamentalsOnsite - OpenAIHardMachine Learning EngineerStreaming Entropy with Numerical Stability
Implement an online, numerically stable algorithm to compute Shannon entropy over an unbounded stream of categorical tokens with O(1) updates.
Coding & AlgorithmsTechnical Screenstreamingmathnumerical-computing - OpenAIHardSoftware EngineerText Editor in Four Stages: Buffer, Undo/Redo, Trie Autocomplete, Collaborative OT
Build a text editor in four stages: a buffer with insert, delete and read, undo and redo with two stacks, trie-based autocomplete ranked by word frequency, and real-time collaborative editing with operational transformation. It tests data structure choice, reversible operations, top-k retrieval and concurrency correctness.
Software Engineering FundamentalsOnsite - OpenAIMediumSoftware EngineerThree-Card Game: Deal Hands, Rank Them, Then Add a Flush Category
A two-part card game coding exercise: deal three cards to each player from one deck, show every hand and pick the winner using three of a kind, pair and high card, then add a flush category between them. It tests hand representation, within-category comparison, tie handling and code that extends cleanly when a rule changes.
Software Engineering FundamentalsTechnical Screen - OpenAIHardSoftware EngineerToy Language Types: Render Types and Signatures, Infer Generic Return Types
Model the types of a toy programming language, with primitives, generic type variables and nested tuples, render types and function signatures as strings, then infer a call's concrete return type by binding generics consistently across arguments. It tests recursive data modeling, exact formatting and type inference with clear errors.
Software Engineering FundamentalsOnsite - OpenAIMediumMachine Learning EngineerTrack Expiring GPU Credits
Design an in-memory credit ledger to track expiring GPU compute credits, support priority consumption, and manage resource debt.
Coding & AlgorithmsOnsiteHeapDesignGreedy - OpenAIHardMachine Learning EngineerTrain a classifier and analyze dataset
This question evaluates proficiency in end-to-end supervised machine learning workflows—covering data validation, exploratory data analysis, preprocessing, model training and selection, evaluation metrics and calibration, fairness assessments, and reproducibility—and tests competencies in applied machine learning engineering, statistical reasoning, and model governance within the Machine Learning domain. It is commonly asked in technical interviews because it verifies practical implementation skills and judgment for deploying reliable classifiers, aligning metrics to business goals and diagnosing performance and fairness across slices, with emphasis on practical application informed by conceptual understanding.
Machine LearningTechnical Screen - OpenAIMediumMachine Learning EngineerTrain and analyze a classifier
This question evaluates proficiency in end-to-end machine learning engineering, including exploratory data analysis, time-aware train/validation/test splitting, model baseline and improvement, class imbalance strategies, leakage-safe hyperparameter tuning, metric computation and calibration, error analysis, reproducible training pipelines with CLI/config/seed control, explainability (feature importance/SHAP and ablations), and documentation of risks, fairness checks and monitoring hooks. It is commonly asked to assess practical ability to manage the full ML lifecycle and data hygiene in production-like scenarios, testing applied Data Manipulation (SQL/Python) and Machine Learning competencies with an emphasis on practical application while also requiring conceptual understanding of evaluation, calibration and fairness.
Data Manipulation (SQL/Python)Technical Screen
OpenAI