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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 2311–2340 of 3640 results
- MicrosoftMediumSoftware EngineerLongest Single-Letter Substring After at Most k Letter Replacements
A string problem: given uppercase letters and a budget of k single-letter changes, find the longest contiguous substring that can be turned into one repeated letter. It tests efficient substring scanning with letter counts and careful reasoning about when a candidate substring stays valid.
Coding & AlgorithmsOnsite - MicrosoftMediumSoftware EngineerMaximize Equal Array Length After Contiguous Sum Merges
Determine the maximum possible length of two identical arrays formed by repeatedly merging adjacent elements of two given positive-integer arrays, or return -1 if impossible.
Coding & AlgorithmsOnsiteTwo PointersGreedyArrays - MicrosoftMediumSoftware EngineerMaximize profit with bounded sell window
This question evaluates proficiency in array algorithms, time and space complexity analysis, and techniques for bounded-range optimization and streaming adaptation.
Coding & AlgorithmsOnsite - MicrosoftMediumApplied ScientistMaximum Subarray Sum of an Array Repeated K Times
A coding question that first asks for the largest sum of a non-empty contiguous subarray, then for the same quantity when the array is written out k times back to back. It tests subarray reasoning across copy boundaries, all-negative inputs, and sums that overflow 32-bit integers.
Coding & AlgorithmsOnsite - MicrosoftEasySoftware EngineerMeasure Every Lake on a Map Tile, Listed in Scan Order
Compute the area of every water body on a rectangular map tile, reported in the order a row-by-row scan first touches each one; tests connected components on a grid and avoiding recursion limits on huge regions.
Coding & AlgorithmsOnsitegridgraph-traversaldfs - MicrosoftMediumMachine Learning EngineerMeasure LLM Quality and Detect Hallucinations, Then Implement an Evaluation Component
A hands-on LLM evaluation exercise on measuring model quality, comparing prompt or model versions, and detecting hallucinations against supplied context. It also asks for a small Python groundedness scorer that flags unsupported sentences and aggregates a hallucination rate, testing evaluation judgment and clean, well-tested code.
Machine LearningOnsite - MicrosoftMediumSoftware EngineerMedian of Every Fixed-Length Sliding Window in an Integer Array
A coding problem that slides a window of fixed length k across an integer array and asks for the median of every window position, returned as floats in window order. It tests keeping the middle of a changing collection available as elements enter and leave, exact handling of even-sized windows, and overflow-safe averaging.
Coding & AlgorithmsOnsite - MicrosoftMediumSoftware EngineerMerge multiple sorted arrays using min-heap
This question evaluates algorithm design and data structure proficiency, focusing on merging multiple sorted sequences and reasoning about time and space complexity for large numbers of arrays and elements.
Coding & AlgorithmsOnsite - MicrosoftMediumSoftware EngineerMinimize Fuel Cost Across Cities
Calculate the minimum monetary cost to travel between two cities in a road network where fuel is consumed per unit distance and can be stockpiled with unlimited capacity at local city prices.
Coding & AlgorithmsOnsiteGraphDijkstraShortest Path - MicrosoftMediumSoftware EngineerMinimum Number of Rooms to Host Overlapping Meetings
A scheduling problem that asks for the fewest rooms needed to hold a set of meetings given as half-open time intervals, where a room freed at a given moment can be reused immediately. It tests interval reasoning, correct handling of shared endpoints and duplicates, and an efficient solution for large inputs.
Coding & AlgorithmsOnsite - MicrosoftMediumSoftware EngineerMinimum Ship Capacity to Deliver Ordered Packages Within a Day Limit
Given package weights in a fixed loading order and a number of days, find the smallest ship capacity that delivers every package within that many days, carrying one contiguous run of packages per day. It tests reasoning precisely about feasibility, choosing correct bounds and handling large inputs efficiently.
Coding & AlgorithmsOnsite - MicrosoftMediumSite Reliability EngineerOn-call behavioral: judging severity, escalating, and tracing an issue to a recent change
Behavioral incident-response question for a senior reliability role: describe an on-call incident on a large customer-facing service and how you judged severity and escalated, then a case where you tied runtime signals to a recent deployment or feature flag change. It tests triage judgment, coordination and reducing time to resolution.
Behavioral & LeadershipOnsite - MicrosoftMediumSoftware EngineerPeer-to-Peer File Distribution: Discovery, Chunked Transfer and Integrity Checks
A system design interview question asking you to build a peer-to-peer file sharing network where users download large files directly from other users. It tests content identification, peer discovery, chunked parallel transfer with integrity checks, NAT traversal, incentives against free-riders, and keeping files available as peers churn.
System DesignOnsite - MicrosoftMediumSoftware EngineerPopulate next pointers in a perfect binary tree
Evaluates proficiency in tree traversal and in-place pointer manipulation, emphasizing the perfect binary tree invariant and space-time trade-offs; category/domain: Coding & Algorithms. It is commonly asked because it tests ability to perform level-wise linking under an O(1) extra-space constraint and operates at the implementation-level of algorithms and data structures.
Coding & AlgorithmsOnsite - MicrosoftMediumApplied ScientistPredict Employee Attrition from an HR Dataset and Explain Its Drivers
A machine learning design exercise: given a tab-separated HR dataset with features such as age, job role, monthly income and overtime, predict which employees will leave and explain which factors drive attrition. It covers feature processing, model choice, class imbalance, evaluation metrics, threshold selection and interpretability.
ML System DesignOnsite - MicrosoftMediumSoftware EngineerRecover Sorted Digits from Scrambled English Number Words
Recover sorted digits from scrambled English number-word letters, including repeats, and analyze why arbitrary customer vocabularies may lose unique recoverability.
Coding & AlgorithmsOnsite - MicrosoftMediumSoftware EngineerResolve Technical Disagreement and Work Across Different Styles
Discuss technical disagreement and contrasting work styles with fair alternatives, shared evidence, explicit decisions, and practical collaboration changes.
Behavioral & LeadershipOnsite - MicrosoftMediumSoftware EngineerRespond to a Reliability Regression Shortly After Deployment
Respond to a post-deployment latency or reliability regression with scoped diagnosis, safe rollback decisions, customer-impact measurement, and prevention.
Software Engineering FundamentalsOnsite - MicrosoftMediumSoftware EngineerResume Deep Dive: Technical Decisions, Personal Contribution, Challenges, Impact
A resume-driven behavioral interview that walks through a past project in depth: the architecture and technical decisions, what the candidate personally contributed, the hardest challenges, and the measurable impact. It tests ownership, technical judgment and clear, structured storytelling.
Behavioral & LeadershipOnsite - MicrosoftMediumSoftware EngineerReverse linked list in fixed-size groups
This question evaluates proficiency with singly linked list manipulation, pointer/reference management, in-place group operations, and complexity reasoning including time and constant extra space.
Coding & AlgorithmsOnsite - MicrosoftMediumSoftware EngineerRotate a 3×3 digit grid by 180°
This problem tests your ability to perform spatial transformations on a fixed-size 2D structure while maintaining data integrity across a transformation.
Coding & AlgorithmsOnsiteArraysMatrixStrings - MicrosoftMediumSite Reliability EngineerSQL: count files where bull and bear appear as standalone space-delimited words
SQL practice question: given a table of files and their text content, count how many files contain the words bull and bear as standalone, space-delimited words. It tests careful pattern matching, case sensitivity, NULL handling, and returning a row for each word even when its count is zero.
Data Manipulation (SQL/Python)Onsite - MicrosoftHardSoftware EngineerShard a Large Input Embedding Table Across Devices
Compare vocabulary and hidden-dimension embedding sharding through per-rank storage, token routing, hidden-state layout, skew, and downstream communication.
ML System DesignOnsite - MicrosoftHardSoftware EngineerShard an LM Head and Combine Distributed Logits
Shard an LM head by vocabulary or hidden width, distinguishing complete logits from partial dot products and exact distributed top-k from full-distribution sampling.
ML System DesignOnsite - MicrosoftMediumSoftware EngineerSimulate a Throttled Function Wrapper That Keeps Only the Latest Pending Call
A coding simulation of a throttle wrapper: given a cooldown length and sorted call times, report which calls actually run and when, where calls arriving during a cooldown keep only the latest one pending. It tests precise event ordering, an explicit rule for calls at the exact moment a cooldown ends, and an efficient single pass.
Coding & AlgorithmsOnsite - MicrosoftEasySoftware EngineerSizes of 4-Connected Foreground Regions in a Binary Image, in Scan Order
Given a binary image stored as a matrix of 0s and 1s, return the size of every region of horizontally or vertically connected foreground pixels, ordered by when each region is first reached in a top-to-bottom, left-to-right scan. It tests grid traversal, connected components, and handling a single region that covers up to a million pixels.
Coding & AlgorithmsOnsite - MicrosoftHardSoftware EngineerSolve Throughput, Rate Limiting, and LFU
This problem tests your ability to design a system with O(1) time complexity for cache operations and time-window-based request tracking.
Coding & AlgorithmsOnsiteData StructuresHashingSliding Window - MicrosoftHardSoftware EngineerSolve cache, grid path, and substring problems
This problem tests your ability to implement an LRU cache, solve a dynamic programming problem on a grid with constraints, and optimize string searching using the sliding window technique.
Coding & AlgorithmsOnsiteHash MapLinked ListDynamic Programming - MicrosoftMediumSoftware EngineerSolve three scheduling and array problems
This multi-part question evaluates algorithmic problem-solving skills across task scheduling with cooldowns, in-place array deduplication, and string rearrangement to avoid adjacent duplicates, highlighting concepts such as frequency counting, scheduling constraints, and two-pointer or in-place techniques within the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - MicrosoftMediumData ScientistTest classifier difference with McNemar's test
This question tests a data scientist's ability to apply McNemar's test for comparing paired classifiers, a core competency in statistical hypothesis testing and model evaluation. It assesses practical knowledge of contingency table analysis, exact vs. asymptotic tests, confidence interval construction, and multiple testing correction in machine learning contexts.
Statistics & MathOnsite
Microsoft