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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 3511–3540 of 4616 results
- RobinhoodMediumSoftware EngineerCompute dependency load factors in a DAG
This problem tests your ability to model dependencies in a Directed Acyclic Graph (DAG) and calculate the cumulative 'load' contribution of each node, requiring efficient graph traversal techniques like topological sorting or recursion with memoization.
Coding & AlgorithmsTechnical ScreenGraphDAGRecursion - RobinhoodMediumSoftware EngineerCompute nearest gate distance in grid
This problem tests your ability to perform multi-source Breadth-First Search (BFS) on a grid to find the shortest distance from every cell to the nearest target (gate).
Coding & AlgorithmsTechnical ScreenBFSGraphsGrid - RobinhoodEasySoftware EngineerCompute trigger counts in a DAG
This question evaluates understanding of directed acyclic graphs, graph traversal and accumulation of values across dependency edges, as well as algorithmic efficiency for handling large sparse graphs.
Coding & AlgorithmsTechnical Screen - RobinhoodMediumBackend EngineerCount and Rank Words in a Paragraph
This problem tests string manipulation, hash map usage for frequency counting, and custom sorting logic for deterministic ordering.
Coding & AlgorithmsTechnical ScreenStringsHash MapSorting - RobinhoodMediumBackend EngineerCritique a Recent Engineering Project and Explain What You Would Redo
Prepare a candid deep dive on a recent engineering project, including personal ownership, a consequential technical decision, and observed outcomes. Identify a real weakness, trace its cause, and explain what you would redesign today.
Behavioral & LeadershipTechnical Screen - RobinhoodMediumBackend EngineerDeep-Dive a Distributed Service Project
This question assesses a candidate's ability to articulate the architecture, constraints, and operational challenges of a distributed system they previously owned, while demonstrating clarity in personal impact and technical decision-making.
Behavioral & LeadershipTechnical ScreenSystem DesignDistributed SystemsCommunication - RobinhoodMediumSoftware EngineerDesign a Reliable Distributed Job Scheduler
This question tests the ability to design a distributed, fault-tolerant job scheduler capable of handling job lifecycle states, worker coordination, and consistent scheduling across multiple tenants.
System DesignTechnical ScreenDistributed SystemsSchedulingReliability - RobinhoodEasySoftware EngineerDesign a distributed job scheduler service
This question evaluates understanding of distributed systems and microservice architecture, scheduling and timeout semantics, fault tolerance, scalability, and data modeling for job metadata, run history, and logs.
System DesignTechnical Screen - RobinhoodMediumSoftware EngineerDesign a job scheduler with SLA and logs
This question tests the ability to design a distributed, fault-tolerant job scheduling system capable of meeting strict SLAs and providing audit-ready logging.
System DesignTechnical ScreenDistributed SystemsTask QueuesScalability - RobinhoodMediumSoftware EngineerDesign a secure trading app on AWS
This System Design question evaluates secure cloud-based architecture on AWS, covering competencies in authentication and authorization, PII handling and auditability, API and data model design, and scalable low-latency market-data retrieval.
System DesignTechnical Screen - RobinhoodEasySoftware EngineerDesign an iOS Timer App with Consistent State and Asynchronous UI Updates
Design an iOS timer around explicit state transitions, clock-based elapsed time, main-thread UI updates, callback ownership, and lifecycle behavior.
Software Engineering FundamentalsTechnical Screen - RobinhoodEasySoftware EngineerDesign in-memory payment and friendship system
This question evaluates object-oriented design skills, stateful in-memory data structures, request processing, and correctness constraints such as friend relationships, unique request IDs, and atomic balance transfers.
Coding & AlgorithmsTechnical Screen - RobinhoodMediumData ScientistDiagnose Decline in First Day Funding Rate
Diagnose Decline in First Day Funding Rate evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - RobinhoodMediumSoftware EngineerFlatten Fractional-Share Inventory and Record Trade Logs
Process fractional-share buys and sells with exact hundredth units, whole-share market flattening, dollar-order conversion, and ordered inventory-perspective logs.
Coding & AlgorithmsTechnical Screen - RobinhoodMediumData ScientistIdentify Overlapping Sessions and Optimize Coverage
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Identify Overlapping Sessions and Optimize Coverage states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - RobinhoodMediumData ScientistIdentify Top Users with Declined Transactions in SQL
This question evaluates proficiency in SQL data manipulation, specifically aggregation, window functions, rolling 24-hour time-window analytics, NULL handling, and conditional classification via CASE WHEN within a fraud/risk detection scenario.
Data Manipulation (SQL/Python)Technical Screen - RobinhoodMediumData ScientistIdentify Transactions During 'Golden' Membership Period
This question evaluates proficiency in temporal data manipulation and aggregation, covering SQL date-range joins, window functions for per-user ranking, and Python frequency counting of senders and receivers, and it falls under the Data Manipulation (SQL/Python) domain for data scientist roles.
Data Manipulation (SQL/Python)Technical Screen - RobinhoodMediumSoftware EngineerImplement string-based candlestick classifier
This question evaluates string parsing, streaming input processing, numeric validation, and attention to time/space complexity in the Coding & Algorithms category, focusing on efficient single-pass parsing and O(1) extra space constraints.
Coding & AlgorithmsTechnical Screen - RobinhoodMediumAndroid EngineerJetpack Compose Auto-Scrolling List with a Start/Stop Toggle and Hex Color Switching
Tests Jetpack Compose UI state management, coroutine lifecycle side-effects with LazyListState, and defensive hex color string parsing.
Software Engineering FundamentalsTechnical ScreenAndroidJetpack ComposeCoroutines - RobinhoodMediumData ScientistList Transactions During Active 'Gold' Membership Period
This question evaluates proficiency in SQL-based data manipulation and temporal reasoning, specifically the ability to correlate membership periods with transaction records using relational operations.
Data Manipulation (SQL/Python)Technical Screen - RobinhoodMediumSoftware EngineerReason About Dependency Loading with Topological Sort
Tests graph construction, topological sorting (Kahn's algorithm or DFS), cycle detection, and deterministic tie-breaking for modular dependency resolution.
Software Engineering FundamentalsTechnical ScreenGraphTopological SortHeap - RobinhoodMediumBackend EngineerScale Word-Frequency Processing Beyond One Machine
This question tests the ability to design a distributed data processing pipeline that handles large-scale text files by balancing memory constraints, horizontal scalability, and data integrity.
System DesignTechnical ScreenDistributed SystemsMapReduceScalability - RobinhoodMediumSoftware EngineerWalk through project scope, ownership, and decisions
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Walk through project scope, ownership, and decisions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - RobinhoodMediumData ScientistWrite SQL and Python for transaction analytics
This question evaluates data manipulation competency in SQL and Python, covering normalization of transaction direction, JOINs and CASE logic, window functions for ranking and aggregation, and designing single-pass counting algorithms for streaming-like inputs.
Data Manipulation (SQL/Python)Technical Screen - RobinhoodHardData EngineerWrite SQL to analyze CA residency history
This question evaluates a candidate's ability to write SQL for temporal state reconstruction, including correct joins on composite keys, interpreting edit/audit logs, and reasoning about inclusive/exclusive timestamps.
Software Engineering FundamentalsTechnical Screen - RobinhoodMediumData ScientistWrite SQL to localize trading drop contributors
This question evaluates proficiency in SQL-based data manipulation and analytics, including cohorting by signup month, daily aggregation of executed trades per active user, segmentation by platform and geolocation, and competency with joins, timestamps, and operational flags.
Data Manipulation (SQL/Python)Technical Screen - RobloxHardFrontend EngineerBuild a Configurable Two-Player Tic-Tac-Toe Board in React
Tests your ability to architect a scalable, accessible React component with dynamic state, efficient win-detection logic for large grid sizes, and robust handling of prop updates.
Software Engineering FundamentalsTechnical ScreenReactFrontendState Management - RobloxMediumData ScientistCompare ROW_NUMBER, RANK, and DENSE_RANK for Top-k Results
Compare ROW_NUMBER, RANK, and DENSE_RANK with ties, exact-row limits, distinct score levels, and deterministic top-k semantics.
Data Manipulation (SQL/Python)Technical Screen - RobloxMediumData ScientistCompute ARPDAU/ARPPU by country
This question evaluates data manipulation and analytics skills for computing user- and revenue-based metrics (ARPDAU, ARPPU), focusing on aggregation, multi-key joins, deduplication, time-window filtering, and correct revenue attribution.
Data Manipulation (SQL/Python)Technical Screen - RobloxHardData ScientistDemonstrate fit with quantified stories and motivations
This question evaluates a Data Scientist's behavioral and leadership competencies, including storytelling with quantified impact, ownership of technical decisions, trade-off analysis, error detection and correction, motivation, team collaboration, and end-to-end project thinking.
Behavioral & LeadershipTechnical Screen
Robinhood
Roblox