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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 7381–7410 of 9403 results
- RobinhoodHardSoftware EngineerExplain Project Complexity and Scalability in a Deep Dive
Prepare a project deep dive that explains data flow, business invariants, personal ownership, measured bottlenecks, and credible scalability tradeoffs.
Behavioral & LeadershipOnsite - RobinhoodMediumSoftware EngineerExplain auth, key rotation, secrets, and incident response
This question tests your knowledge of secure microservice communication, the lifecycle management of sensitive credentials, and the operational procedures for mitigating security breaches.
Software Engineering FundamentalsOnsiteSecurityMicroservicesAuthentication - 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 - RobinhoodMediumSoftware EngineerGive a Project Deep Dive Grounded in Personal Ownership
Tests your ability to present a deep dive into an impactful software project you led or contributed heavily to, emphasizing architectural trade-offs, personal ownership, failure modes, and measurable outcomes.
Software Engineering FundamentalsOnsiteProject Deep DiveSystem ArchitectureBehavioral - RobinhoodMediumSoftware EngineerGive a Technical Deep Dive into a Software Project
Practice a project deep dive covering architecture, personal ownership, implementation decisions, validation, outcomes, and lessons learned.
Software Engineering FundamentalsOnsite - RobinhoodMediumSoftware EngineerHandle security vs velocity conflicts across teams
This question evaluates a candidate's competency in balancing security requirements with product delivery speed, encompassing risk assessment, stakeholder management, trade-off communication, and ownership of execution and follow-through.
Behavioral & LeadershipOnsite - 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 EngineerMaintain Fractional Stock Inventory Across Orders
Simulate sequential customer fractional buy and sell orders, using scaled integer arithmetic to maintain the firm's remaining inventory between 0 and 1 share while tracking whole-share market executions.
Coding & AlgorithmsOnsitesimulationmathhash-table - RobinhoodMediumSoftware EngineerParse Requests and Compute Balances
This problem tests your ability to parse structured text commands, manage relational state between users, and implement transactional logic with integrity constraints.
Coding & AlgorithmsOnsiteHash MapGraphParsing - RobinhoodMediumSoftware EngineerProduce a Deterministic Course Plan
Return the lexicographically smallest valid course order from prerequisite pairs, or report a cycle. Handle duplicate edges, malformed IDs, self-dependencies, empty course sets, and large graphs with deterministic topological sorting.
Coding & AlgorithmsOnsite - 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 - RobinhoodMediumProduct ManagerWhy this role and team scope?
Prepare Robinhood PM recruiter-screen answers for role motivation and team scope. Covers crypto wallet and on-ramp product interest, cross-functional team size, data-science partnership, and scope of impact.
Behavioral & LeadershipHR 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 - RobloxMediumData ScientistAnalyze Recent Orders Dataset with Python/pandas
This question evaluates proficiency in data manipulation and aggregation using Python/pandas, including extracting per-user maximums, computing overall summary statistics, and producing daily aggregates from time-stamped records.
Data Manipulation (SQL/Python)Onsite - RobloxHardData ScientistApply Bayes' rule to compute posterior
Evaluates understanding of Bayes’ rule and basic probability concepts—specifically computing a posterior probability P(A|B) and the marginal likelihood P(B) from a prior and likelihoods—in the Statistics & Math domain at a foundational-to-intermediate abstraction level.
Statistics & MathOnline Assessment - 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 - RobloxMediumSoftware EngineerBuild an Auto-Rotating Traffic Light in Vanilla JavaScript Without a Framework
A frontend coding question asking for a traffic light that cycles through its colors automatically, built with plain HTML, CSS, and JavaScript and no framework. It tests state machine design, timer management and cleanup, efficient DOM updates, accessibility, and how to test time-based UI code.
Software Engineering FundamentalsOnsite - RobloxMediumData ScientistChoose best/worst actions under OA pressure
This question evaluates judgment and leadership competencies in data science — including risk assessment, stakeholder impact analysis, integrity under time pressure, and handling failing tests and collaborator input — and falls under the Behavioral & Leadership category.
Behavioral & LeadershipOnline Assessment - 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 - RobloxEasyData ScientistCompute A/B test sample size and Bayes posterior
This question tests the ability to calculate required sample size for a frequentist A/B test using power analysis and to perform a Bayesian update for a Bernoulli process.
Statistics & MathOnline AssessmentStatisticsA/B TestingBayesian Inference - 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
Robinhood
Roblox