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Software Engineer 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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- 11
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Showing 1891–1920 of 2810 results
- OpenAIHardSoftware EngineerKey-Value Store Persistence: Length-Prefixed Bytes, Size-Capped Chunks, Thread Safety
A three-part key-value store exercise: serialize keys, values and their lengths into bytes and persist them on shutdown, split the saved data into chunks of a given maximum size, and discuss making the existing code safe for multithreaded use. It tests byte-level encoding, correct restore and concurrency reasoning.
Software Engineering FundamentalsTechnical Screen - OpenAIHardSoftware EngineerLab Robot Job Dispatcher with Backoff, Quarantine and Prereqs
Implement an in-memory job dispatcher where failed jobs wait out a per-job backoff, keep their original queue position, and get quarantined after repeated failures, then add prerequisite jobs with cascading quarantine. Tests state modeling, dual-heap scheduling, and online topological ordering.
Software Engineering FundamentalsTechnical Screenheapschedulingstate-machine - OpenAIMediumSoftware EngineerLease-Based Job Queue for Flaky Render Workers
Build an in-process job queue that hands out time-limited leases. A job is never lost when a worker crashes, hangs or fails, and jobs that always fail are dead-lettered after a retry limit. Tests state machines, fencing tokens, thread safety and clock-injected tests.
Software Engineering FundamentalsTechnical Screenconcurrencyqueuesfault-tolerance - OpenAIMediumSoftware EngineerManage GPU Credits with Expiration
This question evaluates data-structure design and algorithmic reasoning for time-based resource accounting, including handling expiring credits and out-of-order operations while maintaining efficient (logarithmic) performance constraints.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerMerge overlapping intervals
This question evaluates algorithmic problem-solving skills focused on interval manipulation, sorting and merging logic, and time/space complexity analysis within the Coding & Algorithms domain, emphasizing practical application.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerMinimize deaths in spreading plant infection
This problem tests your ability to simulate a state-based grid propagation and optimize intervention timing using either greedy or dynamic programming approaches.
Coding & AlgorithmsTechnical ScreenSimulationBFSGrid - OpenAIMediumSoftware EngineerOptimize C++ Performance with Provided Concurrency
This question evaluates a developer's skills in C++ performance engineering and concurrent systems, covering profiling, bottleneck identification (e.g., cache locality and lock contention), and code-level performance reasoning to improve throughput and latency.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerOrder Recipe Prep Steps Into the Smallest Valid Sequence
Return a deterministic, lexicographically smallest valid ordering of named prep steps with dependency constraints, correctly including steps with no prerequisites and steps unconnected to any dependency.
Coding & AlgorithmsTechnical Screentopological-sortgraphsheap - OpenAIMediumSoftware EngineerOrder Tasks with Dependencies Using a Deterministic Topological Sort
Tests deterministic topological sorting of a directed acyclic graph using Kahn's algorithm and a priority queue to guarantee lexicographical tie-breaking.
Coding & AlgorithmsTechnical Screengraphtopological-sortheap - OpenAIMediumSoftware EngineerParse and build binary data in Python
This question evaluates proficiency in binary data handling and serialization/deserialization in Python, including little-endian integer encoding, length-prefixed payloads, robust error handling for short reads and invalid lengths, and testability and performance considerations.
Data Manipulation (SQL/Python)Technical Screen - OpenAIHardSoftware EngineerPrint Shop Job Queue: Retries, a Poison Queue and Job Prerequisites
Implement an in-memory job queue for a print shop where workers reserve, complete, or fail jobs, failed jobs retry up to a limit before landing in a poison queue, and a second part adds job prerequisites with cascading failure.
Software Engineering FundamentalsTechnical Screenqueuesstate-machinesretries - 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 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 - 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 - 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 - 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 - 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 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 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 - OptiverHardSoftware EngineerAnalyze an Unfair-Coin Bankroll Game
This problem tests probability theory and expected value calculations in the context of a game with an unfair coin and a bankroll constraint.
Statistics & MathTechnical ScreenProbabilityExpected ValueRecurrence Relations - OptiverHardSoftware EngineerCalculate the Probability That Two Dice Sum to Seven
This question tests fundamental understanding of discrete probability, combinatorics, and the impact of conditional dependencies on outcomes.
Statistics & MathTechnical ScreenProbabilityCombinatoricsStatistics - OptiverHardSoftware EngineerCargo Order Allocation Across Departing Planes
This question evaluates competence in deterministic resource allocation, stateful simulation, and capacity-management under time constraints, exercising algorithmic reasoning and data-structure handling within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - OptiverMediumSoftware EngineerCompare common data structures and uses
Compare common data structures and uses evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - OptiverMediumSoftware EngineerCompute expectations, conditionals, odds, and distributions
This question evaluates proficiency in fundamental probability and statistics concepts — including expected value and variance, conditional probability, discrete arrival modeling, betting odds and the Kelly criterion, and combinatorics for draws without replacement — and is categorized under Statistics & Math.
Statistics & MathTechnical Screen - OptiverMediumSoftware EngineerCount nonnegative buy/sell sequences
This question evaluates combinatorial reasoning and algorithmic analysis by asking for the count of constrained buy/sell sequences, testing competence in counting under constraints and reasoning about sequence invariants.
Coding & AlgorithmsTechnical Screen - OptiverMediumSoftware EngineerDecide and implement DP/heap and approximation
This question evaluates dynamic programming for counting constrained subsequences, priority-heap implementation and API robustness for job scheduling, and heuristic approximation methods for NP-hard selection problems, along with algorithmic complexity analysis.
Coding & AlgorithmsTechnical Screen - OptiverMediumSoftware EngineerDemonstrate task switching and memory strategies
This question evaluates task-switching ability, working-memory management, interference control, and error-recovery strategies—core executive functions involved in rapid stimulus–response mappings.
Statistics & MathTechnical Screen
OpenAI
Optiver