Robinhood interview questions

Showing 1–30 of 60 results

• Aggregate user logs into 30-minute sessionsHard

  This question evaluates data engineering competencies in time-series sessionization, datetime parsing and arithmetic, grouping and aggregation, distinct-count computation, and CSV log processing.

  RobinhoodData EngineerCoding & AlgorithmsTechnical Screen
• Build a Chainable Rectangle Manipulation APIMedium

  This problem tests your ability to design a fluent interface (method chaining) that manages an internal queue of asynchronous operations to ensure tasks execute sequentially.

  RobinhoodFrontend EngineerSoftware Engineering FundamentalsTechnical Screen
• Build a Weekly CalendarMedium

  This question evaluates frontend UI engineering skills, focusing on interactive interface construction, event handling, and state modeling to maintain a single source of truth for events in a weekly calendar grid, and it belongs to the web frontend development and UI/state-management domain.

  RobinhoodFrontend EngineerCoding & AlgorithmsOnsite
• Clarify Friendship Rules and Money-Transfer Semantics Before Choosing an AlgorithmMedium

  Clarify friendship and money-transfer requirements, separate graph reachability from accounting, and reason about a conditional implementation and invariants.

  RobinhoodSoftware EngineerSoftware Engineering FundamentalsOnsite
• Compute Load Factors in a Service Dependency DAGMedium

  Calculate downstream request multipliers for services in a directed acyclic graph (DAG) starting from an entrypoint service, accounting for converging dependency paths and unreachable nodes.

  RobinhoodSoftware EngineerCoding & AlgorithmsTechnical Screen
• Compute dependency load factors in a DAGMedium

  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.

  RobinhoodSoftware EngineerCoding & AlgorithmsTechnical Screen
• Compute nearest gate distance in gridMedium

  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).

  RobinhoodSoftware EngineerCoding & AlgorithmsTechnical Screen
• Compute trigger counts in a DAGEasy

  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.

  RobinhoodSoftware EngineerCoding & AlgorithmsTechnical Screen
• Count Unique Dependents in a Referral DAGHard

  Count unique direct and transitive dependents in a DAG, preserving edge direction, ignoring unknown endpoints, and handling shared descendants without double-counting.

  RobinhoodSoftware EngineerCoding & AlgorithmsOnsite
• Count and Rank Words in a ParagraphMedium

  This problem tests string manipulation, hash map usage for frequency counting, and custom sorting logic for deterministic ordering.

  RobinhoodBackend EngineerCoding & AlgorithmsTechnical Screen
• Create OHLC Aggregates from Tick Data in PythonMedium

  This question evaluates a candidate's ability to perform time-series bucketing and OHLC aggregation from tick data, testing skills in data parsing, stateful aggregation, and handling missing-interval forward-filling; it falls under Data Manipulation (SQL/Python) and assesses practical application rather than purely conceptual understanding.

  RobinhoodData ScientistData Manipulation (SQL/Python)Onsite
• Critique a Recent Engineering Project and Explain What You Would RedoMedium

  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.

  RobinhoodBackend EngineerBehavioral & LeadershipTechnical Screen
• Deep-Dive a Distributed Service ProjectMedium

  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.

  RobinhoodBackend EngineerBehavioral & LeadershipTechnical Screen
• Defend the Complexity and Scalability of a ProjectMedium

  Prepare a project deep dive that withstands repeated questions about technical difficulty and scalability. Define your ownership, defend a genuine trade-off with evidence, identify current bottlenecks, and propose incremental scaling only when measurable signals justify it.

  RobinhoodSoftware EngineerBehavioral & LeadershipOnsite
• Define and Calculate Employee Referral CountsMedium

  Implement an algorithm to compute direct and total downstream referral counts for every employee in a directed graph that may contain duplicates, converging paths, and cycles.

  RobinhoodSoftware EngineerSoftware Engineering FundamentalsOnsite
• Design Payment Processing with Idempotency and ReconciliationMedium

  Design a resilient payment processing system that interfaces with third-party payment gateways, guarantees exactly-once execution via idempotency, manages complex payment state machines, and resolves discrepancies via reconciliation.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design Real-Time Analytics Pipeline with Kafka and FlinkMedium

  This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Design Real-Time Analytics Pipeline with Kafka and Flink states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  RobinhoodData ScientistBehavioral & LeadershipOnsite
• Design a Cron Job Scheduler for 100K Jobs With At-Least-Once ExecutionMedium

  A system design question about a cron job scheduler that stores about 100,000 recurring job definitions, runs up to 10,000 jobs at once and guarantees at-least-once execution. It tests data modeling, including whether a schedule belongs on the job, finding and dispatching due jobs at scale, and failure handling with leases and retries.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design a Distributed Scheduler with At-Most-Once RunsHard

  Design a distributed scheduler around strict at-most-once run starts, durable identities, ambiguous crashes, SLA failures, queue recovery, logs, and notification outboxes.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design a Fault-Tolerant Distributed Job SchedulerMedium

  This question tests the ability to design a distributed, fault-tolerant system capable of scheduling and executing tasks reliably at scale, emphasizing durability, state management, and consistency.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design a Photo Album AppMedium

  This question evaluates proficiency in frontend system design, specifically client-side component and data architecture, state management and normalization, real-time synchronization, and large-media upload flows; it sits in the System Design domain with a Frontend Engineer focus and tests practical application of these competencies.

  RobinhoodFrontend EngineerSystem DesignOnsite
• Design a Photo Management ServiceMedium

  This question evaluates a candidate's ability to design scalable, reliable photo management systems, focusing on API design, storage architecture, metadata modeling, album management, and operational concerns for large numbers of users and photos.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design a Reliable Distributed Job SchedulerMedium

  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.

  RobinhoodSoftware EngineerSystem DesignTechnical Screen
• Design a Task Scheduler and ExecutorMedium

  Design a high-scale task scheduler for one-time, cron-like, fixed-rate, and fixed-delay execution. Cover versioned task and attempt states, due-time indexing, safe concurrent claims, retries, leases, backpressure, idempotency, recurrence semantics, and recovery.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design a constrained cache and secure string validatorMedium

  This question tests the ability to implement a thread-safe, size-constrained cache (LRU-like) and robust string validation logic for identifying malformed or potentially malicious input strings.

  RobinhoodSoftware EngineerCoding & AlgorithmsOnsite
• Design a distributed job schedulerMedium

  This question tests the ability to design a fault-tolerant, scalable distributed system capable of scheduling one-time and recurring background tasks with guaranteed execution semantics.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design a distributed job scheduler serviceEasy

  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.

  RobinhoodSoftware EngineerSystem DesignTechnical Screen
• Design a job scheduler with SLA and logsMedium

  This question tests the ability to design a distributed, fault-tolerant job scheduling system capable of meeting strict SLAs and providing audit-ready logging.

  RobinhoodSoftware EngineerSystem DesignTechnical Screen
• Design a live and historical stock quote API fed by a redundant exchange trade feedMedium

  A system design question that asks for a stock quote API serving live prices at about 10 million requests per second and one-day, one-month and one-year history at about 1 million, fed by two redundant exchange trade connections. It tests sequence-number arbitration, gap replay, fan-out of live state, bar aggregation and caching at scale.

  RobinhoodSoftware EngineerSystem DesignOnsite
• Design a referral leaderboard with chain-based countsMedium

  This question evaluates a candidate's ability to model and compute transitive referral counts using graph-like structures and efficient data structures, testing skills in algorithm design, counting, and sorting within the Coding & Algorithms domain.

  RobinhoodSoftware EngineerCoding & AlgorithmsOnsite