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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
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- 546
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- 11
- Topics
- 8
- Languages
Showing 2611–2640 of 9403 results
- CrowdstrikeMediumSoftware EngineerImplement an In-Memory Key-Value Cache with Expiry, Then Sketch a Redis-Like Server
Implement an in-memory key-value cache in the spirit of Redis, with get, set, delete and per-key expiry, then briefly discuss how a Redis-like server is built and where caches fit in a system. It tests data structure choices, expiry and eviction logic, thread safety, and practical knowledge of caching patterns.
Software Engineering FundamentalsOnsite - CrowdstrikeMediumSoftware EngineerMaximize the minimum value along a grid path
This problem tests your ability to combine binary search on the answer with graph traversal techniques (BFS/DFS/Union-Find) to solve optimization problems on a 2D grid.
Coding & AlgorithmsOnsiteBinary SearchBFSDFS - CrowdstrikeMediumSoftware EngineerReview a Sample Python Function Aloud and Label Every Finding by Severity
Review a short hypothetical Python function that builds a user profile from a database query and a billing-service call, narrating your reasoning aloud. The exercise tests how you read unfamiliar code and whether every comment is clearly labeled as must-fix, could-improve or a personal preference.
Software Engineering FundamentalsOnsite - CrusoeMediumSoftware EngineerCalculate charge with a single price override
This problem tests your ability to handle overlapping time intervals and apply conditional overrides to calculate the total charge for a billing period.
Coding & AlgorithmsTechnical ScreenIntervalsArraysLogic - CrusoeEasySoftware EngineerDesign a Slack-Like Messaging Platform
Design a real-time team messaging platform supporting channels, direct messages, message persistence, and presence tracking. The design tests your ability to model conversations, ensure reliable and ordered message delivery, and handle high-throughput fan-out.
System DesignOnsiteDistributed SystemsWebSocketsPub/Sub - CrusoeEasySoftware EngineerImplement Interval Overrides and Top-K Strings
Implement interval override logic for half-open ranges and calculate the top-k labels based on total active duration with lexicographical tie-breaking.
Coding & AlgorithmsOnsiteintervalssortinghash-table - CubistMediumSoftware EngineerDesign a class to submit jobs with dependencies and track their status
Design and implement a job tracker class that accepts job submissions with dependencies, hands out jobs that are ready to run, and reports each job's status. It tests state-machine design, dependency-graph bookkeeping, handling of failures and cycles, and thread safety when several workers call the class at once.
Software Engineering FundamentalsTechnical Screen - CubistMediumSoftware EngineerDesign a reusable event-driven framework for trading strategies
Design a reusable, event-driven framework for trading strategies that a team can keep extending after a take-home handoff. It tests event modeling and dispatch ordering, strategy interfaces, backtest and live parity, order and risk management, and the tests and documentation that make a framework maintainable.
Software Engineering FundamentalsTechnical Screen - CubistMediumSoftware EngineerRebuild a binary search tree from its postorder traversal in linear time
Rebuild a binary search tree with distinct values from its postorder traversal and return the rebuilt tree's preorder traversal. The problem tests BST ordering properties, traversal orders, and meeting a strict O(n) time bound on inputs that include deeply skewed trees.
Coding & AlgorithmsTechnical Screen - CurrentMediumSoftware EngineerDescribe a previous project and outcomes
Describe a previous project and outcomes 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 - CurrentHardSoftware EngineerDesign a metrics monitoring system
Design a metrics monitoring system evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignTechnical Screen - CursorMediumSoftware EngineerBuild a Merkle Tree over a Directory with Hash Lookup and Tree Diff
Implement a Merkle tree over a real directory in Python, with N-ary directory nodes, a build method, a hash lookup by path, and a diff that compares two trees, and write the tests yourself. It tests deterministic hashing design, file-system traversal, pruning identical subtrees, and disciplined testing under time pressure.
Software Engineering FundamentalsTechnical Screen - CursorHardSoftware EngineerBuild a Streaming Markdown Code Fence Parser
Tests streaming string processing, finite state machine design, and edge-case handling for incrementally received Markdown code fences.
Software Engineering FundamentalsTechnical ScreenStreamingFinite State MachineParsing - CursorMediumSoftware EngineerConnect a Project Deep Dive to Engineering Career Decisions
Connect a technical project deep dive with engineering career decisions, using clear ownership, interface trade-offs, validation, and lessons learned.
Behavioral & LeadershipTechnical Screen - CursorMediumBackend EngineerDesign Scalable Notification Rate Limiter
This question evaluates expertise in designing distributed rate-limiting systems with hierarchical quotas, focusing on concurrency control, exact rolling-window counting, and correctness under concurrent stateless servers; it belongs to the System Design domain and tests practical application of distributed systems, storage, and API design as well as conceptual understanding of atomicity and consistency. It is commonly asked to assess reasoning about atomic decision-making across multiple scopes, scalability and partitioning strategies, handling reconfiguration and operational concerns, and the trade-offs between correctness and system performance (English).
System DesignTechnical Screen - CursorMediumSoftware EngineerDesign Versioned IDE Settings for Users and Teams
Design a distributed, hierarchical configuration management service for an IDE that synchronizes versioned settings across individual users, multiple teams, and workspaces while supporting offline modifications and deterministic conflict resolution.
System DesignTechnical ScreenDistributed SystemsOffline SyncData Modeling - CursorMediumSoftware EngineerDesign a Durable Cron Job Scheduler
Design a cron scheduler with durable occurrences, timezone rules, missed-run policies, worker leases, idempotent dispatch, and failure recovery.
System DesignTechnical Screen - CursorMediumSoftware EngineerHash a Repository with a Merkle Tree and Find Changed Files
Hash a repository with canonical Merkle nodes, compare changed subtrees, report file changes, and account for symlinks, cached hashes, and snapshot limits.
Software Engineering FundamentalsTechnical Screen - CursorMediumSoftware EngineerImplement Deterministic Merkle Hashing for a Repository
Implement an incremental, deterministic Merkle tree for a virtual repository file system with stable serialization, child ordering, and ancestor cache invalidation.
Software Engineering FundamentalsTechnical ScreenMerkle TreeData StructuresFile Systems - CursorMediumSoftware EngineerImplement a Merkle Tree for Repository Contents
Implement a Merkle tree to model repository file systems and efficiently compute differences between two repository states using subtree hashes.
Software Engineering FundamentalsTechnical ScreenMerkle TreeTreesHashing - CursorHardSoftware EngineerImplement a Merkle-tree repo diff
This question evaluates a candidate's understanding of Merkle trees, filesystem-aware hashing, directory traversal, and diff algorithms for detecting file-level changes.
Coding & AlgorithmsTechnical Screen - CursorMediumSoftware EngineerImplement and Explain a Merkle Tree
Tests understanding of cryptographic hash trees (Merkle trees), including tree construction, odd-node handling, proof generation, and verification.
Software Engineering FundamentalsTechnical Screencryptographydata-structurestrees - DRWEasyQuantitative TraderAnalyze distribution of a 3-dice product
This question tests the ability to analyze the probability distribution of the product of three independent discrete random variables and apply these statistical properties to practical risk management.
Statistics & MathOnline AssessmentProbabilityExpectationStatistics - DRWMediumMachine Learning EngineerBuild pipeline for imbalanced classification
This interview question evaluates ML product requirements, data/labeling, modeling, serving architecture, evaluation, monitoring, and trade-offs in a realistic interview setting. A strong answer for Build pipeline for imbalanced classification states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
ML System DesignOnline Assessment - DRWMediumData ScientistCompute Markov steady state and expectations
Compute Markov steady state and expectations evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - DRWEasyData EngineerCompute a Year-End Balance with Monthly Card Fees
This problem tests logic implementation and data structure traversal, requiring the integration of conditional logic (fee waivers) into a sequential processing pipeline.
Coding & AlgorithmsOnline AssessmentData ProcessingLogicAggregation - DRWEasyQuantitative TraderCompute expected arc length on a circle
This question evaluates understanding of geometric probability, order statistics on a circle, and expectation computation for continuous random variables.
Statistics & MathOnline Assessment - DRWEasyData EngineerDelete the Fewest Characters to Avoid Triple Repeats
This problem tests string manipulation, greedy algorithm logic, and the ability to track character frequency counts to identify and prune violations of a constraint.
Coding & AlgorithmsOnline AssessmentStringsGreedyArrays - DRWEasyData ScientistDerive eigenvalues and sum for inverse matrix
Derive eigenvalues and sum for inverse matrix evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - DRWMediumData ScientistDifferentiate sample vs population standard deviation
This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Differentiate sample vs population standard deviation states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathTechnical Screen
Crowdstrike
Cursor
DRW