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Coding & Algorithms 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
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 1051–1080 of 1706 results
- OpenAIHardSoftware EngineerImplement follow graph with snapshots
This problem tests your ability to design a versioned, immutable, or persistent data structure that supports efficient graph modifications and point-in-time snapshot queries.
Coding & AlgorithmsTechnical ScreenPersistent Data StructuresGraphsVersion Control - OpenAIMediumSoftware EngineerImplement follow graph with snapshots and recommendations
This question evaluates design and implementation skills for mutable graph data structures with point-in-time snapshotting and recommendation ranking, testing knowledge of data structures, versioning, graph traversal, and algorithmic time/space complexity analysis.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement in-memory DB querying
This question evaluates a candidate's competency in data structures, algorithms, and systems-level thinking for implementing query processing in an in-memory database, including projection, predicate filtering, ordering, and index design.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement in-memory KV store with serialization
This question evaluates skills in designing and implementing an in-memory key-value store with serialization, testing data structure design, API design (set/get/serialize/deserialize), serialization format selection, type fidelity for common Python types, and robust error handling.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement node messaging and path discovery
This question evaluates skills in distributed systems and algorithms, including reliable message-passing between adjacent nodes, graph traversal and path discovery, fault-tolerant protocol design, and message/time complexity analysis.
Coding & AlgorithmsTechnical Screen - OpenAIMediumSoftware EngineerImplement persistent key-value store
This question evaluates competency in implementing an in-memory key-value store with persistence, covering concepts such as serialization, durability, data structure management, and basic I/O handling.
Coding & AlgorithmsTechnical Screen - OpenAIHardSoftware EngineerImplement type AST and infer generics
This problem tests your ability to design a recursive data structure for an abstract syntax tree and implement a unification-based type inference engine for a simple functional language.
Coding & AlgorithmsTechnical ScreenASTType InferenceRecursion - OpenAIMediumSoftware EngineerInfection Spread Simulation with Death Threshold
Implement a cellular automaton simulating epidemic spread on a 2D grid with simultaneous infection and mortality transitions until convergence.
Coding & AlgorithmsTechnical Screenmatrixsimulationbreadth-first-search - 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 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 - 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 - 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 - 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 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 - 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 - OpendoorHardBackend EngineerExecute a TTL Key-Value Store with Transactions
This problem tests the implementation of an in-memory key-value store supporting TTL expiration, atomic transactions with rollback capabilities, and logical time-based validation.
Coding & AlgorithmsTechnical ScreenHashMapsTransactionsTTL - 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 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 EngineerDesign a circular queue data structure
This problem tests your ability to implement a fixed-capacity circular queue using a static array, focusing on efficient pointer arithmetic and state management.
Coding & AlgorithmsTechnical ScreenData StructuresArraysQueues - OptiverMediumSoftware EngineerDesign a queue and analyze tradeoffs
This question evaluates understanding of FIFO data structures, algorithmic complexity analysis, memory and cache behavior, and concurrent access concerns.
Coding & AlgorithmsTechnical Screen
OpenAI
Optiver