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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 31–60 of 70 results
- LinkedInMediumSoftware EngineerShortest Substring Containing Every Character of a Pattern
Return the shortest substring of a string that contains every character of a pattern with matching multiplicity, case-sensitively, choosing the leftmost substring on ties and an empty string when none exists. Tests efficient substring search and careful character-count bookkeeping.
Coding & AlgorithmsOther - MetaMediumSoftware EngineerAdd Two Arbitrarily Long Non-Negative Integers Given as Decimal Strings
Add two non-negative integers that are given as decimal digit strings, possibly thousands of digits long, and return the sum as a string without converting to built-in numbers. Tests digit-by-digit addition with carries, inputs of unequal length and canonical output without leading zeros.
Coding & AlgorithmsOther - MetaMediumSoftware EngineerDesign a GPS Fitness Tracking App with Activity Uploads and a Friends Feed
A system design interview question asking you to build a GPS fitness-tracking app in the style of Strava, where athletes record runs and rides, save routes and follow friends' activity feeds. It tests offline-tolerant recording, duplicate-free uploads, storage for large GPS tracks, feed fan-out and privacy controls.
System DesignOther - MicrosoftMediumSoftware EngineerDesign a Real-Time Collaborative Document Editor with Concurrent Editing
A senior-level system design prompt asking for a browser-based document editor where many people edit the same file at once, similar to Google Docs. It tests concurrency control for simultaneous edits, real-time sync, durable storage with version history, sharing permissions, and how the service scales and recovers from failures.
System DesignOther - MicrosoftMediumSoftware EngineerDesign and Implement a Worker Thread Pool with Futures and Shutdown
Low-level design and concurrency question: design and implement a fixed-size thread pool with task submission, futures that return results or errors, and graceful or cancelling shutdown. It tests lock and condition variable use, lost wake-ups, policies for rejected work, pool sizing and deadlocks between dependent tasks.
Software Engineering FundamentalsOther - MicrosoftMediumSoftware EngineerImplement a Priority Queue from Scratch with Custom Ordering and Stable Ties
Data structures question that asks you to build a priority queue from scratch with insert, peek, remove-top and size operations, a caller-supplied ordering and stable ties. It tests the choice of underlying structure, invariant-preserving insertion and removal, complexity analysis and edge-case handling.
Software Engineering FundamentalsOther - MicrosoftMediumSoftware EngineerLow-Level Design of a Logging Library Shared by Many Threads
Low-level design question about an in-process logging library that many threads call at the same time. It tests class modeling for loggers, records, formatters and output destinations, plus thread safety, the hand-off to a background writer, ordering, overflow behavior, failure isolation and clean shutdown.
Software Engineering FundamentalsOther - MicrosoftMediumSoftware EngineerMinimum total cost to convert one string into another using weighted character rules
A string transformation problem: convert a source string into a target string using directed, weighted character replacement rules that may be chained at a position. It tests reasoning about multi-step conversions, choosing the cheapest of duplicate rules, detecting impossible positions, and totals beyond the 32-bit range.
Coding & AlgorithmsOther - MicrosoftMediumSoftware EngineerReturn the k values in a sorted array closest to a target, with smaller-value ties
Given a sorted integer list, a count k and a target value, return the k elements closest to the target in ascending order. The problem tests a precise tie rule that favors smaller values, duplicate values, targets outside the array's range, and working efficiently on already sorted input.
Coding & AlgorithmsOther - MongoDBMediumSoftware EngineerSuppress repeat log messages printed within 10 seconds of their last printed occurrence
Coding practice question: process a time-ordered stream of log messages and decide which ones are printed when the same text may print at most once every 10 seconds. It tests tracking state across a stream, exact boundary handling at the 10-second mark, and correctly ignoring suppressed events.
Coding & AlgorithmsOther - NVIDIAMediumSoftware EngineerCount Server Pairs Relayed Through Each Node of a Weighted Tree
Given a weighted tree of servers and a signal speed, count for every server how many pairs of other servers it can relay: both path lengths must be multiples of the speed and the two paths must share no cable. Tests tree traversal, path-length reasoning and careful combinatorial counting.
Coding & AlgorithmsOther - NVIDIAMediumSoftware EngineerNormalize an Absolute Unix-Style File Path to Canonical Form
Convert an absolute Unix-style file path into canonical form by collapsing repeated slashes, dropping current-directory markers, applying parent-directory moves that stop at the root, and treating other dot-only names as ordinary directories. Tests careful string parsing and edge-case handling of path components.
Coding & AlgorithmsOther - NVIDIAMediumSoftware EngineerRestaurant Table Reservations: Availability Search and Conflict-Free Booking
System design question asking for a restaurant table reservation service where diners search availability, book, change and cancel, and restaurants manage tables and hours. It tests the data model, preventing double-booking under concurrency, holds and retries, fast availability search and handling booking spikes.
System DesignOther - NetflixMediumSoftware EngineerDesign a Streaming Subscription System: Billing, Plan Changes and Payment Retries
Design the subscription backend of a video streaming service such as Netflix, covering the subscription lifecycle, recurring billing through an external payment provider, mid-cycle upgrades and downgrades, retries of failed charges, and scaling. It tests data modeling, safe payment handling, concurrency between member actions and billing jobs, and keeping entitlement checks fast.
System DesignOther - NetflixMediumSoftware EngineerRecommend New Friends from a Mutual-Friendship Graph and Scale the Approach
A problem-solving question about recommending new friends from a mutual friendship graph, worked mostly through discussion with a little code and pseudocode. It tests candidate generation and scoring with deterministic tie-breaks, cost in terms of node degree, handling highly connected users, and precomputing and refreshing suggestions at scale.
Software Engineering FundamentalsOther - NielsenMediumSoftware EngineerBehavioral: Walk Through the Project You Are Most Proud Of
A senior behavioral question that asks which project you are most proud of and why, then probes your personal contribution, the hardest decision you made, and the measurable impact. It tests ownership, technical depth, and the ability to explain trade-offs and lessons clearly to an interviewer.
Behavioral & LeadershipOther - NielsenMediumSoftware EngineerDesign a URL Shortening Service: Code Generation, Storage and Fast Redirects
A system design question on building a URL shortening service that turns long links into short codes and redirects visitors quickly at large scale. It tests requirement scoping, capacity estimates, collision-free code generation across servers, storage and caching choices, and how the redirect path behaves under failure.
System DesignOther - NielsenMediumSoftware EngineerPrefix Tree Supporting Insert, Exact Search and Prefix Queries
A coding problem that processes a sequence of insert, exact-match search and prefix-check operations on lowercase words and returns the boolean answers to the queries in order. It tests building a character-level word index and correctly separating whole-word matches from words that are only prefixes of others.
Coding & AlgorithmsOther - NielsenMediumSoftware EngineerSpring Boot Internals and Java 21 Features Behind a Machine Coding Solution
A machine coding follow-up that drills into a Spring Boot service built during the round: startup, auto-configuration, dependency injection and proxies, then the Java 21 features that could improve it, such as sealed types with pattern matching and virtual threads. It tests framework depth and version-aware modern Java knowledge.
Software Engineering FundamentalsOther - OracleMediumSoftware EngineerBehavioral: simplifying a complicated product or system and proving it worked
A behavioral question asking for a complicated product or system the candidate made simpler. It evaluates how they diagnosed the source of the complexity, decided what to remove or hide, brought users and stakeholders along, and measured whether the simplification actually helped.
Behavioral & LeadershipOther - OracleMediumSoftware EngineerMaximum stock trading profit with at most k buy-and-sell transactions
Given daily stock prices and a transaction limit k, compute the maximum profit achievable with at most k buy-then-sell trades while holding at most one share at a time. It tests generalizing a fixed-count trading problem, handling a k larger than the available profitable trades, and tracking state efficiently.
Coding & AlgorithmsOther - OracleMediumSoftware EngineerMaximum stock trading profit with at most two buy-and-sell transactions
A stock trading optimization problem: given daily prices, find the maximum profit using at most two buy-then-sell transactions while holding at most one share at a time. It tests reasoning about splitting the price history into non-overlapping trades and handling falling, flat or steadily rising prices.
Coding & AlgorithmsOther - OracleMediumSoftware EngineerSimulate an LFU cache that evicts the least-used key, breaking ties by recency
Implement and simulate a least-frequently-used cache with fixed capacity that evicts the key with the lowest use count, breaking ties by least recent use. It tests exact eviction semantics, treating updates and reads as uses, and supporting every get and put in constant average time.
Coding & AlgorithmsOther - OtherMediumSoftware EngineerSpreadsheet Formulas, Dependencies, and Circular References
Implement spreadsheet formulas with dependency updates, repeated references, unset cells, and cycle detection that recovers after formulas change.
Coding & AlgorithmsOther - PalantirMediumSoftware EngineerDesign a Real-Time Collision Warning System for Drones in Shared Airspace
Design a system that ingests live telemetry from many drones sharing airspace and warns operators when two of them are predicted to come too close. It tests streaming ingestion, spatial partitioning, trajectory-based conflict prediction, alert delivery and reliability under the latency and safety demands of a real-time system.
System DesignOther - PalantirMediumSoftware EngineerDesign a Tool Registration, Discovery and Safe Execution Layer for LLM Agents
A senior system design question about the platform that lets LLM-driven agents discover and call backend tools. It probes tool registration and discovery, schema definition versus runtime validation of model-generated arguments, the interface between backend services and agents, and patterns for executing actions safely.
System DesignOther - RapidSOSMediumSoftware EngineerDesign the Product Catalog for a Multi-Store Grocery Delivery Marketplace
A senior system design prompt reported from a RapidSOS loop: design the product catalog for a multi-store grocery delivery marketplace like Instacart. It tests modeling shared products versus per-store prices and availability, ingesting messy retailer feeds, store-scoped browse and search, caching, freshness and checkout consistency.
System DesignOther - RevolutMediumSoftware EngineerBuild a Java restaurant table booking service that prevents double bookings
A live Java coding exercise to build a restaurant table booking system while an AI assistant is allowed. It tests domain modeling, correct interval overlap logic for tables, a clear table allocation policy, thread safety, and how the candidate tests and stays in control of generated code under time pressure.
Software Engineering FundamentalsOther - RevolutMediumSoftware EngineerDesign automatic travel insurance enrollment triggered by customer location
A system design exercise for a banking app that automatically enrolls opted-in customers in travel insurance when location signals show they are abroad. It tests requirements scoping, an event-driven pipeline, idempotent enrollment with an insurer, data modeling, scaling reads and writes, and failure handling.
System DesignOther - SalesforceMediumSoftware EngineerBehavioral deep dive: scaling decisions, zero-to-one platforms, traffic spikes, conflict
Hiring manager behavioral round for a senior backend engineer: a deep dive into a system you own with probing on scaling decisions and failure modes, plus stories about building a platform from zero, handling an unexpected traffic spike, resolving cross-team conflict, and motivation for the move.
Behavioral & LeadershipOther
LinkedIn
Meta
Microsoft
MongoDB
NVIDIA
Netflix
Nielsen
Oracle
Palantir
Revolut
Salesforce