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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 2581–2610 of 9403 results
- CoupangMediumSoftware EngineerDesign large video upload for a YouTube-like app
This question evaluates a candidate's ability to design scalable, reliable large-file upload subsystems, testing competencies in distributed storage, resumable transfers, data integrity, processing pipelines, security, and observability.
System DesignOnsite - CoupangMediumSoftware EngineerFind shortest distance between two islands
This question evaluates understanding of grid-graph traversal and shortest-path concepts, including identification of connected components and reasoning about minimal bridging distance between regions.
Coding & AlgorithmsOnsite - CoupangEasySoftware EngineerFind the Closest Value in a Binary Search Tree
This question tests your ability to traverse a binary search tree efficiently by leveraging its ordering property to find the node value closest to a given target number.
Coding & AlgorithmsTechnical ScreenBinary Search TreeBinary TreeTree Traversal - CoupangMediumData ScientistMonthly Cohort Retention
This question tests the ability to transform raw user activity logs into a cohort retention matrix by calculating the time elapsed between a user's first interaction and subsequent activity.
Data Manipulation (SQL/Python)Technical ScreenSQLRetentionCohort Analysis - CoupangMediumData ScientistPredicting the Next Elevator Call Location
This question tests the ability to design a spatio-temporal forecasting system to predict future elevator call locations, focusing on feature engineering, model selection, and handling data sparsity.
Machine LearningTechnical ScreenTime-SeriesFeature EngineeringSpatio-Temporal - CoupangMediumData ScientistReserving an Elevator for Food Deliveries
This question evaluates your ability to design an A/B test for an operational policy change in a high-traffic environment, focusing on cluster randomization, metric selection, and handling network effects.
Analytics & ExperimentationTechnical ScreenA/B TestingExperiment DesignMetrics - CoupangMediumSoftware EngineerWalk Through Your Proudest Project, What Made It Special, and What You Would Change
Behavioral project deep-dive for software engineers: describe the project you are proudest of, what made it distinctive, what you learned, and what you would do differently. It tests concise storytelling, clear personal ownership, technical depth, measurable results, and honest self-reflection on past decisions.
Behavioral & LeadershipOnsite - CourseraHardSoftware EngineerImplement Plurality and Runoff Voting
This question evaluates understanding of voting algorithms, tie-breaking rules, ballot processing, and correctness under edge cases such as incomplete or exhausted ballots, and is commonly asked to assess algorithmic implementation, state simulation, and careful handling of corner cases in interview settings.
Coding & AlgorithmsTechnical Screen - CourseraHardBackend EngineerImplement Popular and Ranked Voting
This question evaluates algorithmic implementation skills and understanding of voting systems, including aggregation of first-place preferences and the conceptual mechanics of elimination-based ranked-choice counting.
Coding & AlgorithmsTechnical Screen - Credit GenieMediumSoftware EngineerImplement FastAPI CRUD endpoints from skeletons
This question evaluates a candidate's ability to implement RESTful CRUD endpoints with FastAPI, focusing on API contract consistency, HTTP status codes and idempotency, input validation and exception handling, and unit testing.
Software Engineering FundamentalsTechnical Screen - Credit GenieMediumSoftware EngineerImplement and analyze number-pattern function
This question evaluates algorithmic thinking and implementation skills related to string construction, time and auxiliary space complexity analysis, and handling boundary/edge-case off-by-one errors.
Coding & AlgorithmsTechnical Screen - Credit GenieMediumSoftware EngineerIntroduce yourself and show mission alignment
This question evaluates behavioral and leadership competencies including communication, mission alignment, expectation-setting, and collaborative API/interface ownership within an ML engineering context.
Behavioral & LeadershipTechnical Screen - CreditkarmaMediumMachine Learning EngineerDesign Personalized Promotion Recommendations
This question tests the ability to design an end-to-end recommendation system for personalized financial promotions, focusing on handling sparse conversion data, real-time feature requirements, and feedback loops.
ML System DesignTechnical ScreenRecommendation SystemsRankingFeature Engineering - CreditkarmaMediumMachine Learning EngineerDesign a Revenue Ranking Platform
This problem tests your ability to design a multi-stage ranking system that balances business revenue goals with user relevance, specifically addressing sparse conversion data and long-term user retention.
ML System DesignOnsiteRankingRecommendationMulti-task Learning - CrestaMediumSoftware EngineerBuild a Tool-Calling Chat Agent That Searches and Books Flights via a REST API
An AI-assisted coding round: turn a Python starter script into a terminal chat agent that uses LLM tool calling to search flights, save passenger details and book a flight through a three-endpoint REST API. It tests tool schemas, a multi-step tool loop, ID handling, booking safeguards and error handling.
Software Engineering FundamentalsOnsite - CrestaMediumSoftware EngineerCount the Leaves Left on a Grid After a Sequence of Wind Gusts
Simulate wind gusts over a grid in which every cell holds a number of leaves: each gust shifts all leaves one cell in its direction, and leaves pushed off the edge are lost for good. Return how many leaves remain, testing careful two-dimensional state updates and boundary handling under time pressure.
Coding & AlgorithmsOnline Assessment - CrestaMediumSoftware EngineerDesign a Robust Feature Flag Evaluation Engine
Implement an in-memory feature flag evaluation engine that evaluates flags against user attributes using rule predicates, deterministic percentage rollouts, and a true-wins resolution policy.
Software Engineering FundamentalsOnsiteSoftware ArchitectureData StructuresHashing - CrestaMediumSoftware EngineerDesign an Evaluation Platform for AI Agents Across Prompt and Model Changes
An ML system design question about a platform that lets teams evaluate AI agents and measure how a change of system prompt or model affects quality, tool use and response speed. It tests evaluation design, scoring with references and LLM judges, statistical comparison of versions and scalable execution.
ML System DesignOnsite - CrestaMediumSoftware EngineerDesign sequence decoding with greedy and beam search
This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Design sequence decoding with greedy and beam search states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningTechnical Screen - CrestaMediumSoftware EngineerJob Dispatcher with Least-Loaded, Round-Robin Assignment and Executor Removal
A coding exercise to implement Executor and JobDispatcher classes that send each integer job ID to the executor with the fewest pending jobs, breaking ties round-robin, while executors join and leave. It tests precise tie-break semantics, consistent load tracking, reassigning a removed executor's queued jobs, and edge cases.
Software Engineering FundamentalsTechnical Screen - CrestaMediumSoftware EngineerLongest Overlap Between the End of One String and the Start of Another
Given two strings, return the length of the longest suffix of the first string that is also a prefix of the second. The problem tests precise string indexing, the direction of the overlap, and boundary cases such as no overlap at all or an overlap covering the whole shorter string.
Coding & AlgorithmsOnline Assessment - CrestaEasySoftware EngineerProductionize a Successful Proof of Concept
Explain how to take a successful proof of concept into production, including the engineering and operational gaps that must be closed.
System DesignTechnical Screen - CrestaMediumSoftware EngineerRecorded Walkthrough of a Past AI Project and Your Own Role in It
A recorded behavioral item from a timed online assessment for a forward-deployed AI engineering role: walk through an AI project you built and explain exactly which parts you owned. It tests concise technical storytelling, clear ownership, evaluation and outcomes without a live interviewer to prompt you.
Behavioral & LeadershipOnline Assessment - CrestaMediumSoftware EngineerSearch a Directory Tree for a File and Return Its Absolute Path in Python
Write a Python function that searches a directory and all of its subdirectories for a file matching a requirement and returns the file's absolute path. It tests practical use of os and pathlib, deterministic handling of multiple or missing matches, relative roots, symbolic links and unreadable directories.
Software Engineering FundamentalsOnline Assessment - CriblMediumSoftware EngineerDesign an LLM Log Parsing Workflow
This question evaluates skills in ML-enabled log parsing, schema inference, structured data extraction, and designing scalable, reliable production workflows that combine probabilistic LLMs with deterministic parsers and operational engineering.
ML System DesignTechnical Screen - CrowdstrikeMediumSoftware EngineerCount connected components in a binary grid
This problem tests your ability to model a 2D grid as a graph and use graph traversal algorithms like DFS or BFS to count distinct connected components.
Coding & AlgorithmsOnsiteGraphsDFSBFS - CrowdstrikeMediumSoftware EngineerDesign a Secure, Highly Available Real-Time Event Messaging Platform and Defend It
Design a real-time event messaging platform as a take-home assignment where security and availability come first, then defend it in a live review. It tests durable partitioned delivery, authentication and tenant isolation, multi-zone and regional failover, and the ability to weigh reviewer suggestions and adapt to changed requirements.
System DesignTake-home Project - CrowdstrikeMediumSoftware EngineerDesign a file upload and scanning report system
This problem tests your ability to design a distributed, asynchronous system that handles high-throughput file uploads, coordinates multi-engine security scanning, and provides reporting capabilities.
System DesignOnsiteScalabilityAsynchronousSecurity - CrowdstrikeMediumSoftware EngineerDesign scalable worker pool for template jobs
This question evaluates a candidate's competency in designing scalable, concurrent backend systems, covering distributed worker pools, producer–consumer patterns, queuing, load balancing, fault tolerance, backpressure, and domain-specific considerations like template parsing and caching.
System DesignTechnical Screen - CrowdstrikeMediumBackend EngineerImplement a Risk-Score Priority DetectionStore With Put and GetNext in C++
Implement a C++ DetectionStore whose Put stores security detections with an id, an unsigned risk score and a payload, and whose GetNext removes and returns the next detection by risk score as a unique_ptr. Tests priority-structure choice, ownership semantics, tie and duplicate-id policies, and thread safety.
Software Engineering FundamentalsTechnical Screen
Coupang
Cresta
Crowdstrike