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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 2761–2790 of 2810 results
- WhatnotEasySoftware EngineerRepeatedly Delete Adjacent Duplicate Pairs or Whole Runs of Equal Characters
A string coding problem with two modes: repeatedly delete pairs of equal adjacent characters, or, as the follow-up, delete whole runs of equal adjacent characters, always the leftmost run first, and return what remains. It tests simulating cascading deletions efficiently and handling runs that merge after a deletion.
Coding & AlgorithmsTechnical Screen - WhatnotEasySoftware EngineerSolve Adjacent-Deletion and Sorted-Square Problems
This question evaluates skills in string manipulation and pattern-removal algorithms for adjacent duplicates and k-sized group deletions, as well as array processing and merging techniques for producing sorted squares; it tests understanding of relevant data-structure concepts and merging/two-pointer strategies within the Coding & Algorithms domain. It is commonly asked to assess algorithmic efficiency, correctness under large input constraints and tricky edge cases (such as cascading deletions and negative values), and is primarily a practical implementation task that emphasizes complexity analysis over purely theoretical reasoning.
Coding & AlgorithmsTechnical Screen - WorldquantHardSoftware EngineerCompare Functional and Object-Oriented Python Design
Design and contrast functional versus object-oriented architectures for an in-memory record transformation and enrichment pipeline in Python that requires runtime configuration and cached lookup state. Evaluate both paradigms across state isolation, testability, edge cases, and thread safety.
Software Engineering FundamentalsTechnical Screenpythonsystem-design-principlesfunctional-programming - XPengMediumSoftware EngineerImplement Stable Softmax
This question tests the ability to implement a numerically stable softmax function by handling potential floating-point overflows or underflows common in high-dimensional vector exponentiation.
Coding & AlgorithmsTechnical ScreenNumerical MethodsSoftmaxFloating-Point Arithmetic - XiaohongshuMediumSoftware EngineerFind the Unique Element in Pairs
This problem tests your ability to use binary search on a sorted array to find a unique element where all other elements appear in identical pairs.
Coding & AlgorithmsTechnical ScreenBinary SearchArraysDivide and Conquer - XiaohongshuMediumSoftware EngineerMaximum Profit from One Stock Purchase and a Later Sale
This problem tests the ability to solve the 'best time to buy and sell stock' pattern in O(n) time and O(1) space, identifying the minimum price seen so far to calculate potential profit.
Coding & AlgorithmsTechnical ScreenArraysGreedyOptimization - XiaopengMediumSoftware EngineerMaintain the Median of a Data Stream
This problem tests the ability to maintain dynamic statistics in a data stream using efficient data structures to achieve optimal insertion and retrieval times.
Coding & AlgorithmsTechnical ScreenHeapsData StreamsSorting - ZipHQMediumSoftware EngineerCompute maximum sum in a tree without adjacency
This question evaluates dynamic programming on trees and graph component identification by requiring selection of non-adjacent nodes to maximize a sum, targeting skills in tree algorithms, constraint-based optimization, and rigorous correctness and complexity reasoning.
Coding & AlgorithmsTechnical Screen - ZipHQHardSoftware EngineerDesign in-memory DB with TTL and history
This question evaluates system design skills around building an in-memory database, focusing on API design, data structures, time/version semantics (TTL and time-travel), filtered querying, and complexity reasoning.
System DesignTechnical Screen - ZipHQMediumSoftware EngineerExtend a questionnaire condition evaluator with numeric questions and nested AND/OR logic
A backend practical exercise that extends an existing Python questionnaire parser and condition evaluator. Part one adds numeric questions with numeric comparison conditions; part two adds AND/OR conditions across different questions, including nested groups. Both parts require new automated tests.
Software Engineering FundamentalsTechnical Screen - ZipHQMediumSoftware EngineerFind root IDs and paths
This question evaluates understanding of graph/tree relationships, identification of root nodes, and path reconstruction from parent references, assessing algorithmic reasoning and data-structure familiarity.
Coding & AlgorithmsTechnical Screen - ZipHQHardSoftware EngineerFind the Guaranteed Capture Time in a Turn-Based Graph Game
Solve guaranteed capture time in a finite turn-based graph pursuit game, including Jerry-first moves, staying, optimal adversarial play, and infinite evasion on cycles.
Coding & AlgorithmsTechnical Screen - ZipHQMediumSoftware EngineerMaximize non-adjacent sum on an N-ary tree
This question evaluates skills in tree-based dynamic programming, recursive traversal, and per-node state management for selecting non-adjacent nodes in an N-ary tree.
Coding & AlgorithmsTechnical Screen - ZiplineMediumSoftware EngineerDesign a Checkers Game Simulator
This question evaluates object-oriented design skills, state modeling, rule-based algorithm development for move validation and game-state transitions, API specification, and robust error and edge-case handling.
Software Engineering FundamentalsTechnical Screen - ZiplineMediumSoftware EngineerImplement a Maximum-Tracking Stack
This question evaluates competency in data structure design and algorithmic analysis, focusing on stack operations augmented with maximum-tracking and correctness when multiple maximal elements and ordering constraints are present.
Coding & AlgorithmsTechnical Screen - ZooxMediumSoftware EngineerDesign Nearby Search for Autonomous Vehicles
Design a real-time geospatial search and filtering system for an autonomous vehicle fleet. The service must index streaming vehicle telemetry, handle out-of-order updates, and query nearby eligible vehicles with strict latency bounds.
System DesignTechnical ScreenGeospatialDistributed SystemsStreaming - ZooxMediumSoftware EngineerExplain C++ References, Pointers, Virtual Methods, and Overrides
Tests core C++ object model mechanics, including memory representation of pointers versus references, dynamic dispatch internals, and correct usage of virtual methods and the override specifier.
Software Engineering FundamentalsTechnical ScreenC++Object-OrientedMemory Management - ZooxMediumSoftware EngineerLane-Change Safety and Longitudinal Motion Simulation
Implement a discrete-time kinematic simulator to evaluate whether an autonomous vehicle can safely execute a lane change given adjacent lead and lag vehicles.
Coding & AlgorithmsTechnical Screensimulationkinematicsautonomous-vehicles - ZooxMediumSoftware EngineerThree Array Problems for Trading Geometry and Grouping
Implement three foundational utility functions for an algorithmic trading log analyzer: maximum single-transaction profit, detection of four collinear price points, and deterministic equivalence grouping of trader nicknames.
Coding & AlgorithmsTechnical ScreenArrayGeometryUnion Find - dYdXMediumSoftware EngineerSolve shortest and label-similar paths
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Solve shortest and label-similar paths states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - eBayMediumSoftware EngineerAssign Ads to Browser Positions
This question evaluates algorithmic problem-solving around randomized selection, constraint-based resource allocation, and per-user state management, including enforcing eligibility rules and incrementing display counts.
Coding & AlgorithmsTechnical Screen - eBayMediumSoftware EngineerCount Connected Land Regions
This question evaluates understanding of graph connectivity and grid traversal, specifically the detection of connected components within a 2D matrix. It is commonly asked to assess algorithmic problem-solving, efficiency and handling of matrix-based data structures; it belongs to the Coding & Algorithms domain and tests practical implementation skills alongside conceptual understanding of graph-related complexity under the given input constraints.
Coding & AlgorithmsTechnical Screen - eBayMediumSoftware EngineerDescribe Your Most Technically Difficult Project
This question assesses the candidate's ability to communicate complex engineering challenges, technical decision-making, and the impact of their contributions in a structured manner.
Behavioral & LeadershipTechnical ScreenBehavioralSystem DesignTechnical Communication - eBayMediumSoftware EngineerDesign a Customer Payment Dispute Platform
Design a resilient payment dispute resolution platform that handles dispute lifecycles, evidence management, deadline enforcement, external payment provider integration, and financial ledger auditability.
System DesignTechnical ScreenPaymentsState MachineDistributed Systems - eBayMediumSoftware EngineerDesign a Top-K trending service
This problem evaluates your ability to design a distributed system that aggregates high-velocity event streams to identify the most frequent items within a sliding time window.
System DesignTechnical ScreenDistributed SystemsScalabilityStreaming - eBayMediumSoftware EngineerDesign an Ad Assignment API
This question evaluates a candidate's skill in designing stateful, production-grade HTTP APIs and reasoning about distributed-systems concerns such as idempotency, concurrency control, per-user state management, and observability.
System DesignTechnical Screen - eBayHardSoftware EngineerDetermine Reachability for a Chinese-Chess Horse with Blocked Legs
Determine if a Chinese-chess horse can reach a target coordinate on a 10x9 board while respecting obstacle-blocked destinations and 'hobbled leg' movement constraints.
Coding & AlgorithmsTechnical Screenbfsgraphmatrix - eBayMediumSoftware EngineerDetermine Whether a String Is a Valid Number
Implement a strict numeric string validator that checks whether an ASCII string conforms to valid integer, decimal, and scientific notation formats.
Coding & AlgorithmsTechnical ScreenStringFinite AutomataParsing - eBayMediumSoftware EngineerExplain React Rendering and How You Fixed a Re-render Problem
A frontend experience discussion about React rendering: explain what triggers a render, the render and commit phases, reconciliation and keys, then walk through a rendering performance problem you diagnosed and fixed. It tests accurate React mechanics, measurement-driven optimization and clear communication of past work.
Software Engineering FundamentalsTechnical Screen - eBayMediumSoftware EngineerFind K most frequent elements
This question tests the ability to combine frequency maps with selection algorithms or heap-based structures to efficiently identify top-k elements.
Coding & AlgorithmsTechnical ScreenHash MapHeapBucket Sort
Whatnot
Worldquant
XPeng
ZipHQ
Zipline
Zoox