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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.
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Showing 1111–1140 of 2629 results
- Hive.AiHardSoftware EngineerDetect a Reachable Negative Cycle
This problem tests the implementation of the Bellman-Ford algorithm to identify negative cycles reachable from a source vertex, specifically requiring careful handling of unreachable nodes to avoid incorrect cycle detection.
Coding & AlgorithmsTechnical ScreenGraphsShortest-PathBellman-Ford - Hive.AiHardSoftware EngineerMeasure Water Trapped Between Elevations
This problem tests the ability to solve a classic dynamic programming/two-pointer challenge by calculating the volume of trapped water between bars of varying heights.
Coding & AlgorithmsTechnical ScreenArraysTwo PointersDynamic Programming - Hive.AiHardSoftware EngineerTrack the Median of a Stream
This problem tests your ability to maintain sorted order in a streaming context using balanced data structures to achieve optimal time complexity for insertions and median retrieval.
Coding & AlgorithmsTechnical ScreenHeapsData StructuresStreaming Algorithms - Hive.AiHardSoftware EngineerValidate Adding an Edge to a Directed Acyclic Graph
This problem tests your ability to manipulate graph structures and implement reachability checks, specifically ensuring that adding an edge to a Directed Acyclic Graph (DAG) maintains its acyclic property.
Coding & AlgorithmsTechnical ScreenGraphsDAGDFS/BFS - HouzzMediumSoftware EngineerConvert a Column Number to an Excel-Style Label
Convert one-based spreadsheet columns into A-through-Z and AA-through-ZZ labels, with correct handling of multiples of 26.
Coding & AlgorithmsOnline Assessment - HubSpotMediumSoftware EngineerDesign a bank with scheduled payments and merges
This question evaluates data-structure and algorithm design competencies with emphasis on concurrency, time-based scheduling, aggregation (TopK), transactional consistency, idempotency, and merge semantics for an in-memory banking service, falling under the Coding & Algorithms and system-design domain.
Coding & AlgorithmsOnline Assessment - HubSpotMediumSoftware EngineerDesign and implement a bank account system
This question evaluates a candidate's skills in system design, data modeling, transactional integrity, concurrency control, idempotency, API design, and algorithmic complexity for implementing a minimal banking service.
Coding & AlgorithmsOnline Assessment - HubSpotEasySoftware EngineerFind a special person using knows(a,b)
This question evaluates algorithmic reasoning about pairwise relation inference using an oracle-style knows(a, b) API and the ability to minimize API calls, testing skills in graph modeling and asymptotic analysis.
Coding & AlgorithmsOnsite - HubSpotMediumSoftware EngineerFind spammer with minimal hasMessaged calls
Find the "spammer" account that messaged every other account but received from none, using only a hasMessaged(a, b) oracle. This is the classic find-the-celebrity problem inverted, solved with a two-phase elimination-then-verify algorithm in O(n) oracle calls and O(1) extra space, with full correctness proof and edge-case handling.
Coding & AlgorithmsOnsite - HubSpotMediumSoftware EngineerImplement account CRUD and transfer
This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Implement account CRUD and transfer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnline Assessment - HubSpotMediumSoftware EngineerValidate hiring request under role constraints
This problem tests your ability to manage state mapping and validate cardinality constraints using hash maps, requiring efficient lookups to ensure hiring requests remain within predefined role limits.
Coding & AlgorithmsTechnical ScreenHash MapsData ValidationState Management - Hudson River TradingMediumSoftware EngineerApproach verbose data-structure design
This question evaluates a candidate's ability to design and implement complex data structures, testing algorithmic reasoning, time/space complexity analysis, state modeling, and organization of code and tests.
Coding & AlgorithmsTechnical Screen - Hudson River TradingEasySoftware EngineerBall Position in a Tilting Maze After Timed Tilt Events
Live coding simulation problem: a ball sits in a grid maze on a board that can tilt up, down, left or right or lie flat, and timed events change the tilt. Return the ball's cell at an end time that can be very large. It tests precise timing rules, wall handling and movement code that scales to long time spans.
Coding & AlgorithmsTechnical Screen - Hudson River TradingMediumSoftware EngineerCalculate Completion Time for a Single-Server Reactor Queue
Simulate a single-threaded reactor queue with a bounded buffer to compute the completion timestamp or drop status for each incoming task.
Coding & AlgorithmsTechnical ScreenQueueSimulationArrays - Hudson River TradingEasySoftware EngineerCheck Root-To-Leaf Target Sums In A Binary Tree
This question tests your ability to traverse a binary tree using depth-first search (DFS) or breadth-first search (BFS) while tracking path accumulators and accurately identifying valid leaf nodes.
Coding & AlgorithmsTechnical ScreenBinary TreeDFSRecursion - Hudson River TradingMediumSoftware EngineerCount Digit-Reversal Equivalent Pairs
Count pairs of indices in an integer array whose values share the same canonical digit-reversal form.
Coding & AlgorithmsTechnical ScreenHash TableMathString - Hudson River TradingMediumSoftware EngineerCount Length-3 Chat Substrings with a Vowel
Count the number of distinct length-3 alphabetical substrings in a chat message that contain at least one vowel.
Coding & AlgorithmsTechnical Screenstringsliding-windowhash-set - Hudson River TradingEasySoftware EngineerCount players reaching end with moving watchers
This problem tests your ability to model state transitions over discrete time steps and efficiently track interval coverage using sorting and sweep-line logic.
Coding & AlgorithmsTechnical ScreenSimulationGeometryOptimization - Hudson River TradingMediumSoftware EngineerDetermine Whether Two Integers Sum to a Target
This problem tests proficiency with hash sets to achieve linear time complexity and emphasizes defensive programming practices like input validation and immutability.
Coding & AlgorithmsTechnical ScreenHash SetArraysTwo Pointers - Hudson River TradingHardSoftware EngineerFinal Grid Position Under Timestamped Direction Changes With Dot Obstacles
An object on a grid changes direction whenever a timestamped action arrives and moves one cell per time unit until a blocked cell or the grid edge stops it. The task asks for its cell at a given end time, testing precise reading of the rules, including that dot cells are obstacles, and efficient handling of very large timestamps.
Coding & AlgorithmsTechnical Screen - Hudson River TradingMediumSoftware EngineerFormat an Integer with Thousands Separators
Implement a function that formats a signed integer with a custom thousands separator character without relying on built-in string formatting utilities.
Coding & AlgorithmsTechnical Screenstringmathimplementation - Hudson River TradingHardSoftware EngineerImplement Order Modification Feature
This question evaluates a software engineering competency in modifying and extending a C++ client/server trading system, focusing on state management, input validation, API integration, and maintaining invariants for order lifecycle.
Coding & AlgorithmsOnsite - Hudson River TradingEasySoftware EngineerMaximize Item Counts Under Suffix Budget Queries
Determine the maximum number of items that can be purchased from a suffix of an item array within a given budget for multiple independent queries.
Coding & AlgorithmsHR Screengreedysortingbinary-search - Hudson River TradingMediumSoftware EngineerReturn the K Smallest Integers
Implement an algorithm to extract the k smallest integers from an unsorted list in ascending order, preserving duplicates, and analyze the trade-offs between sorting, heaps, quickselect, and bounded-range approaches.
Coding & AlgorithmsTechnical ScreenHeapQuickselectSorting - Hudson River TradingMediumSoftware EngineerSimulate Alternating Stick Collection for a Nest
Tests simulation logic, two-pointer state management, turn alternation, and handling conditional decision rules with edge cases.
Coding & AlgorithmsTechnical ScreenTwo PointersSimulationGreedy - Hudson River TradingMediumSoftware EngineerSimulate Players Moving Under a Watcher's Gaze
Simulate the movement and freezing of players on a 1D track under the gaze of a moving watcher who reverses direction at specified times.
Coding & AlgorithmsTechnical Screensimulationarraystwo-pointers - Hudson River TradingEasySoftware EngineerSmallest Integer Point Lit by the Most Street Lamps on a Line
Online assessment coding problem: street lamps on a number line each light a closed interval around their position, and you must return the integer point lit by the most lamps, choosing the smallest such point on ties. It tests interval overlap counting over very large coordinate ranges.
Coding & AlgorithmsTechnical Screen - Hudson River TradingMediumSoftware EngineerSolve Watcher Simulation And Integer Conversion
This question evaluates event-driven simulation and discrete-time state modeling for tracking multiple agents under dynamic visibility constraints, together with low-level numeric string conversion and edge-case handling for 32-bit signed integers.
Coding & AlgorithmsTechnical Screen - Hudson River TradingMediumSoftware EngineerTest easy–medium array/string tasks
This question evaluates a candidate's ability to design concise, robust test cases and translate edge-case reasoning into concrete inputs and expected outputs for array and string problems, reflecting skills in input validation, correctness assurance, and handling varied data characteristics.
Coding & AlgorithmsTechnical Screen - IBMMediumSoftware EngineerBreak Adjacent Duplicate Characters
Tests string traversal, run-length counting, and greedy optimization to determine the minimum character replacements needed to eliminate adjacent identical characters across a list of words.
Coding & AlgorithmsOnline AssessmentStringsGreedyAlgorithms
HubSpot
Hudson River Trading
IBM