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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 5761–5790 of 5874 results
- Wells FargoMediumSoftware EngineerReason About Kafka Consumers and Partitions
This question tests your understanding of Kafka's consumer group protocol, partition assignment logic, and the mechanics of horizontal scaling in distributed message queues.
Software Engineering FundamentalsTechnical ScreenKafkaDistributed SystemsMessaging - WhatnotHardSoftware EngineerBuild User Journey Path Summary
This question evaluates the ability to transform unordered user action logs into a trie-like path tree, exercising skills in grouping and time-sorting per user, maintaining stable insertion order, counting distinct users per prefix, and producing deterministic preorder string output.
Coding & AlgorithmsTechnical Screen - WhatnotMediumSoftware EngineerBuild a Tic-Tac-Toe App
This question evaluates proficiency in interactive UI development and stateful game logic, including turn management, board state representation, win/draw detection, input validation, and reset flow.
Coding & AlgorithmsTechnical Screen - WhatnotEasySoftware EngineerCheck Whether a String Can Become a Palindrome by Deleting at Most One Character
A string coding problem that asks whether a lowercase string can be turned into a palindrome by deleting at most one character, returning a boolean. It tests careful handling of mismatched characters, strings that are already palindromes, and an efficient solution for strings of up to 100,000 characters.
Coding & AlgorithmsTechnical Screen - WhatnotMediumSoftware EngineerContent Safety Filter
Tests string tokenization, interval tracking, and Trie-based multi-word pattern matching to redact prohibited phrases from live-stream messages.
Coding & AlgorithmsTechnical ScreenStringTrieHash Table - WhatnotEasySoftware EngineerCount User Journey Prefixes
Process timestamped user activity logs to reconstruct chronological action sequences and count the frequency of user journey prefixes up to length k.
Coding & AlgorithmsOnline Assessmenthash-mapsortingstrings - WhatnotMediumSoftware EngineerDesign a Charity Donation Website
Tests your ability to architect a resilient, high-throughput charity donation platform with strict payment idempotency, asynchronous transaction processing, real-time campaign counters, and financial auditability.
System DesignTechnical ScreenPaymentsDistributed SystemsIdempotency - WhatnotMediumSoftware EngineerDesign a Direct Messaging System for an E-commerce Marketplace
Design a scalable 1:1 direct messaging platform for an e-commerce marketplace that supports real-time chat, message ordering, read receipts, and offline push notifications across multiple devices.
System DesignTechnical ScreenDistributed SystemsMessagingWebSockets - WhatnotMediumSoftware EngineerDesign an Online Coding Contest Platform
This problem tests your ability to design a distributed architecture for an online coding platform, focusing on secure code execution, high-concurrency submission handling, and real-time leaderboard updates.
System DesignTechnical ScreenDistributed SystemsSandboxingScalability - WhatnotEasySoftware EngineerDesign an Online Coding Judge
This question evaluates system design and scalability skills, including distributed architectures, API and data model design, secure sandboxed code execution, artifact storage with signed URLs, and operational concerns such as observability, fault tolerance, and security.
System DesignTechnical Screen - WhatnotMediumSoftware EngineerDot Product of Two Vectors (Dense, then Sparse)
Tests data structure design and algorithmic optimization for sparse vector operations, transitioning from standard array traversal to pointer-based or hash-based solutions that scale with non-zero elements.
Coding & AlgorithmsTechnical Screenarrayhash-tabletwo-pointers - WhatnotMediumSoftware EngineerKnight Dialer: Count Dialable Digit Sequences
Calculate the number of distinct n-digit phone numbers reachable by standard chess knight moves on a numeric keypad, modulo 10^9 + 7.
Coding & AlgorithmsTechnical Screendynamic-programminggraphcombinatorics - WhatnotHardSoftware EngineerMerge Two Sorted Arrays
Implement a linear-time merge of two sorted arrays into a new sorted array using two pointers, preserving duplicates without modifying the input arrays.
Coding & AlgorithmsTechnical Screenarraystwo-pointerssorting - WhatnotMediumSoftware EngineerPropose and Validate a Mobile App Improvement
This question evaluates product design and system-design skills for mobile applications, including product thinking, high-level implementation planning, experimentation design, and metrics-driven decision-making within the system design category.
System DesignTechnical Screen - WhatnotHardSoftware EngineerRemove All Adjacent Duplicate Pairs
Implement an algorithm to repeatedly eliminate adjacent identical character pairs from a string until no adjacent duplicates remain, handling Unicode inputs in linear time.
Coding & AlgorithmsTechnical Screenstackstringsunicode - 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 - WorkdayMediumSoftware EngineerBuild a Fuzzy Keyword Index
This problem tests your ability to design an efficient data structure for performing fuzzy keyword lookups using edit distance constraints on a static corpus of strings.
Coding & AlgorithmsOnsiteStringsTrieHash Map - WorkdayMediumSoftware EngineerDesign AI-Powered Document Search
This question assesses the ability to design an end-to-end, scalable pipeline for ingesting, processing, and indexing heterogeneous documents (PDFs, images, text files) to support AI-driven semantic search.
ML System DesignOnsiteSystem DesignML EngineeringPipelines - WorkdayEasySoftware EngineerExplain What You Value in Your Next Engineering Role
This question assesses your self-awareness, alignment with organizational culture, and your ability to articulate professional priorities through past experiences.
Behavioral & LeadershipHR ScreenCareer GrowthCompany CultureSelf-Reflection - 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 - WorldquantMediumSoftware EngineerCount Unordered Combinations of Unlimited Coins
Count distinct ways to reach a target with unlimited coins, treating different orders of the same denominations as one combination.
Coding & AlgorithmsOnline Assessment - 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 flush and straight groups in cards
This question evaluates array and string manipulation, grouping and sequence-detection competencies, specifically handling same-rank aggregation and same-suit consecutive runs with overlap and maximality considerations.
Coding & AlgorithmsOnsite
Wells Fargo
Whatnot
Worldquant
XPeng
ZipHQ