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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 1381–1410 of 4616 results
- DisneyMediumMachine Learning EngineerBuild Naive Bayes spam classifier with F1
This question evaluates understanding of probabilistic text classification with Naive Bayes, text preprocessing and feature extraction, and use of the F1 score for performance measurement in a binary spam detection task.
Machine LearningTechnical Screen - DisneyHardSoftware EngineerDesign a personalized recommendation system
This question evaluates a candidate's competency in ML system design and recommender systems engineering, covering data ingestion, feature stores, candidate generation, ranking, online serving, experimentation, and operational considerations.
ML System DesignTechnical Screen - DisneyMediumSoftware EngineerImplement a Set Data Structure with a Resizable Array, Then Improve It with Hashing
Tests low-level data structure design by implementing a set from scratch using an array-backed hash table, focusing on collision resolution, dynamic resizing, load factor management, and amortized complexity.
Software Engineering FundamentalsTechnical ScreenData StructuresHash TableArrays - DisneyMediumSoftware EngineerThread-Safe Buffered Batch Writer for Streaming Records into a Database
Design and implement a thread-safe batch buffer that collects streaming records from multiple producer threads and flushes them to a database using batch inserts based on size, timeout, or shutdown triggers.
Software Engineering FundamentalsTechnical ScreenConcurrencyMultithreadingData Structures - DistylHardSoftware EngineerDesign a Grounded LLM Assistant for Case Preparation
Design an enterprise-grade, retrieval-grounded LLM assistant for litigation teams to summarize discovery documents and draft case briefs with strict matter isolation, citation provenance, contradiction detection, and injection guardrails.
ML System DesignTechnical ScreenRAGLLM SafetyInformation Retrieval - DockerMediumSoftware EngineerDesign a container image registry
This problem tests your ability to design a distributed, content-addressable storage system that handles large binary blobs and metadata while optimizing for read/write performance and storage efficiency.
System DesignTechnical ScreenDistributed SystemsStorageScalability - DockerMediumSoftware EngineerEvaluate an arithmetic expression
This problem tests the ability to parse and evaluate arithmetic expressions involving addition, subtraction, multiplication, and division, requiring careful handling of operator precedence and parsing multi-digit integers.
Coding & AlgorithmsTechnical ScreenStackParsingString Manipulation - DocuSignMediumSoftware EngineerCollapse runs of adjacent anagrams in a word list
Given a list of lowercase words, repeatedly delete any word that is an anagram of the word immediately before it, and return what remains in its original order. The task tests anagram comparison, reasoning about how repeated deletions interact, and producing a unique, order-preserving result.
Coding & AlgorithmsTechnical Screen - DocuSignMediumSoftware EngineerFind maximum island sum and required indices
This question evaluates grid-based graph traversal and connected-component aggregation skills, including handling positive and negative cell values, tie-breaking by row-major indices, and computing maximum component sums.
Coding & AlgorithmsTechnical Screen - DoorDashHardAnalytics EngineerAllocate Support Cost and Diagnose Decline
This question evaluates operational analytics competencies including cost allocation and attribution for support work, root-cause diagnosis of KPI regressions, and metric design for complaint-driver identification and prevention.
Analytics & ExperimentationTechnical Screen - DoorDashMediumData ScientistAnalyze Driver Requests for Food Delivery Orders
This question evaluates data manipulation and analytical SQL skills in the Data Manipulation (SQL/Python) domain, focusing on window functions for ranking and temporal comparison, joins, and aggregation when analyzing orders and driver requests.
Data Manipulation (SQL/Python)Technical Screen - DoorDashMediumSoftware EngineerAnswer rapid-fire behavioral questions
Answer rapid-fire behavioral questions evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - DoorDashHardData ScientistAssess Success Criteria for Bike-Courier Delivery Launch
Evaluates marketplace analytics for launching a bike-courier delivery option in dense delivery markets. Strong answers define stakeholder value, success metrics, market selection, phased rollout, guardrails, and causal evaluation under network effects.
Analytics & ExperimentationTechnical Screen - DoorDashMediumSoftware EngineerBuild a Delivery Payout Calculation API
Build a payout endpoint that retrieves delivery activity and accrues 30 cents per minute for each concurrent order. The solution covers interval sweeps, malformed events, exact money, day boundaries, final rounding, upstream timeouts, retry limits, caching, and layered tests.
Software Engineering FundamentalsTechnical Screen - DoorDashMediumSoftware EngineerBuild a Three-Service Refund Workflow over HTTP
Implement and orchestrate a multi-service refund pipeline over HTTP, ensuring idempotent execution, safe concurrency limits, and crash recovery across separate process boundaries.
Software Engineering FundamentalsTechnical Screendistributed-systemshttp-apisidempotency - DoorDashMediumSoftware EngineerCalculate Courier Earnings
This question evaluates algorithmic problem-solving with emphasis on temporal interval aggregation, handling overlapping events, and applying conditional rate multipliers under specified business rules.
Coding & AlgorithmsTechnical Screen - DoorDashHardSoftware EngineerCalculate Daily Driver Pay
This question evaluates event-driven time-interval processing, interval-overlap arithmetic, rate computation, and robustness to malformed, duplicate, or unordered events when aggregating a driver's pay from a day's log.
Coding & AlgorithmsTechnical Screen - DoorDashMediumData ScientistCalculate Late Delivery Percentage and Top Customers
This question evaluates data manipulation and aggregation skills for a Data Scientist role, focusing on date handling, computing the percentage of late orders, and ranking customers using SQL or Python.
Data Manipulation (SQL/Python)Technical Screen - DoorDashEasyData ScientistCalculate Monthly Restaurant Sales Growth
This problem tests the ability to aggregate transactional data by month and use window functions to calculate percentage growth between consecutive periods while handling null values.
Data Manipulation (SQL/Python)Technical ScreenSQLWindow FunctionsAggregation - DoorDashMediumData ScientistCalculate power and test duration
This question evaluates proficiency in statistical power analysis, sample size calculation for proportions, hypothesis testing for two-sided z-tests, and practical experiment duration estimation for A/B testing.
Statistics & MathTechnical Screen - DoorDashEasySoftware EngineerCompute Courier Delivery Pay
This question tests the ability to handle time intervals and calculate cumulative earnings based on overlapping delivery pay rates.
Coding & AlgorithmsTechnical ScreenArraysIntervalsGreedy - DoorDashMediumSoftware EngineerCompute Differences Between Catalog Trees
This question evaluates proficiency in tree algorithms and hierarchical data comparison, including simultaneous traversal, subtree sizing, key-based node identity, and time/space complexity reasoning, and is commonly asked to assess algorithmic problem-solving and trade-off analysis when comparing structured datasets.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerCompute Driver Pay with Double-Pay Windows
This question evaluates a candidate's ability to perform interval arithmetic and aggregation for time-based pay computations, including handling overlapping intervals, half-open boundaries, capped double-pay application, and special-case handling for canceled orders.
Coding & AlgorithmsTechnical Screen - DoorDashEasySoftware EngineerCompute Nearest Destination Distances
This problem tests your ability to use Multi-Source Breadth-First Search (BFS) to find the distance from every empty cell to the nearest destination in a grid.
Coding & AlgorithmsTechnical ScreenBFSGraphsGrid - DoorDashMediumSoftware EngineerCompute courier pay with peak-hour rules
This question evaluates a candidate's data manipulation skills and competency in implementing business rules, including robust error handling, aggregation for per-day totals, minimum-pay enforcement, and time-window (peak-hour) pay adjustments.
Data Manipulation (SQL/Python)Technical Screen - DoorDashMediumSoftware EngineerCompute delivery times on a grid
This question evaluates understanding of graph traversal and shortest-path algorithms, grid-based pathfinding, and data structure selection for representing sparse or large grids within the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerCompute earliest arrival in time-grid
This question evaluates algorithmic problem-solving and pathfinding skills on grid-based graphs, focusing on modeling time-dependent traversal constraints and reasoning about efficient search and supporting data structures.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerCompute nearest dashmart and busiest assignments
Compute nearest dashmart and busiest assignments evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - DoorDashMediumSoftware EngineerCompute nearest dashmart distances for queries
This question evaluates a candidate's understanding of graph traversal and shortest-path computation on grids, spatial reasoning about obstacles and sources, and the ability to analyze algorithmic scalability and complexity when answering many queries.
Coding & AlgorithmsTechnical Screen - DoorDashMediumData ScientistCompute sample sizes and error control
This question evaluates proficiency in experimental design and applied inferential statistics—specifically sample size calculation for means and proportions, non-inferiority testing, multiple-comparison error control, cluster-randomized design effects, and sequential monitoring boundaries—within the Statistics & Math domain for a Data Scientist role. It is commonly asked to measure the ability to apply statistical formulas and error-control principles under practical constraints, balancing power and type I error while accounting for clustering and interim looks; the assessment emphasizes practical application grounded in conceptual understanding of inferential methods.
Statistics & MathTechnical Screen
Disney
DocuSign
DoorDash