Snowflake interview questions

Showing 31–60 of 130 results

• Deep-Copy a Linked List with Random PointersMedium

  Implement a deep copy of a linked list where each node has both a next pointer and an arbitrary random pointer, ensuring all reachable nodes and relationships are replicated without modifying the original list.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Delete the Fewest Tree Nodes to Meet a Height LimitMedium

  Find a minimum-cardinality set of tree-node deletions under child-promotion semantics using height-budget dynamic programming and explicit solution reconstruction.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Describe navigating ambiguous, repetitive questioningMedium

  This question evaluates a Data Scientist's skills in stakeholder communication, ambiguity management, diagnostic reasoning to identify misaligned goals or definitions, adaptive framing between technical and plain-language explanations, trade-off analysis under time pressure, and delivering measurable outcomes.

  SnowflakeData ScientistBehavioral & LeadershipTechnical Screen
• Design a Cron Job SchedulerMedium

  This question evaluates skills in designing reliable distributed schedulers, including durable state modeling, concurrency and race-condition reasoning, idempotency, and fault-tolerant handoff semantics, and is commonly asked to assess a candidate's ability to guarantee correctness and coordination when multiple replicas must manage recurring job triggers. Categorized under system design and distributed systems with overlap into data modeling and consistency, it emphasizes practical application of architectural and operational trade-offs rather than purely theoretical concepts.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design a Distributed Job Scheduler with Cron, Pause and ResumeMedium

  Design a job scheduler service that runs one-time and cron jobs, supports pausing and resuming, and dispatches work to an unlimited pool of workers. It tests due-job indexing, claim and lease protocols, pause semantics, at-least-once execution with idempotency, and handling top-of-the-hour spikes.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design a Geolocation Search ServiceMedium

  This question tests your ability to design a scalable spatial indexing system capable of performing range-based queries (e.g., 'find all points of interest within 5km') while maintaining high availability and low latency.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design a Photo Album Backend: Upload Consistency, Deduplication and ScalingMedium

  A backend system design prompt for a photo album service where users upload photos and organize them into albums. It probes keeping a metadata database and blob storage consistent on upload, showing new photos instantly despite processing lag, blocking duplicate uploads, and when a relational database stops scaling.

  SnowflakeSoftware EngineerSystem DesignOnsite
• Design a Pipeline That Distills Reusable Agent Skills for Enterprise CustomersMedium

  Design a pipeline that automatically extracts reusable agent skills for enterprise customers from traces and documents, validates them and delivers them to agents. It tests LLM system design, outcome labeling, offline evaluation against a baseline, tenant isolation, versioning and drift monitoring.

  SnowflakeMachine Learning EngineerML System DesignOnsite
• Design a Priority Task Executor with Duplicate Task IDsHard

  This problem tests your ability to design a thread-safe task scheduler that handles duplicate task IDs while ensuring each unique task is executed exactly once based on priority and submission time.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsOnsite
• Design a REST API Abstraction LayerHard

  This question evaluates system design and API design competencies, focusing on creating a REST API abstraction layer and internal SDK that address cross-cutting concerns like reliability, observability, security, versioning, and contract/interface modeling.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design a Reliable Job SchedulerHard

  This problem tests the ability to design a distributed, fault-tolerant job scheduler capable of handling task persistence, concurrency, and strict timing requirements at scale.

  SnowflakeSoftware EngineerSystem DesignOnsite
• Design a Shared User Quota Service That Never OverdrawsMedium

  Design a quota service that several services draw from for each user, where the balance must never be overdrawn under highly concurrent requests and must stay strongly consistent. It tests atomic conditional updates, reserve-and-commit APIs with idempotency, replication choices, and scaling a single hot user's quota.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design a Thread-Safe Multi-Rule Rate LimiterHard

  This problem tests the ability to design a thread-safe, flexible rate-limiting system that handles multiple constraints, atomic permit management, and graceful error handling.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• Design a concurrent web crawlerHard

  This problem evaluates your ability to design a distributed, concurrent web crawling architecture that balances high throughput with politeness policies, concurrency control, and robust state management.

  SnowflakeSoftware EngineerSystem DesignOnsite
• Design a disk-backed KV store under contentionEasy

  This problem tests the ability to design a persistent key-value store that balances disk I/O, memory caching, and thread safety under high concurrency.

  SnowflakeSoftware EngineerSystem DesignOnsite
• Design a distributed system end-to-endHard

  This question evaluates a candidate's ability to design scalable, multi-tenant distributed analytics platforms, testing competencies in distributed systems architecture, data layout and storage, query planning and execution, metadata management, consistency and replication strategies, fault tolerance, observability, and capacity planning.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design a distributed tree node counterMedium

  Design a distributed tree node counter 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.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design a multi-tenant quota systemHard

  This question evaluates a candidate's ability to design a global multi-tenant quota service, testing competencies in distributed systems, data consistency, concurrency control, API and storage modeling, and scalability within the System Design domain.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design an A/B test for ML model launchHard

  This question evaluates a data scientist's competence in experimental design, statistical power analysis, sequential monitoring, covariate adjustment (e.g., CUPED), and practical operational concerns like guardrails, interference, and ramping for ML model launches.

  SnowflakeData ScientistAnalytics & ExperimentationTechnical Screen
• Design an Audit Logs ServiceMedium

  Tests the ability to design an immutable, highly available, multi-tenant audit logging service that supports high-throughput ingestion and tamper-evident storage while providing fast, tenant-scoped querying.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design an Interactive Query Execution NotebookMedium

  Tests your ability to design an asynchronous, scalable system for executing interactive SQL queries and streaming execution state and tabular results back to web clients.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design an analytic warehouse for event dataMedium

  This question evaluates a candidate's competency in data warehousing and engineering for analytics, including event-level schema and partitioning, slowly changing dimensions, idempotent ingestion and deduplication, derived metrics modeling, and query performance and cost trade-offs using SQL/Python.

  SnowflakeData ScientistData Manipulation (SQL/Python)Onsite
• Design an in-memory filesystem and circular queueMedium

  This question evaluates a candidate's skills in data-structure and algorithm design, API specification, correctness reasoning, and time/space complexity analysis within the Coding & Algorithms domain by combining an in-memory hierarchical filesystem design with a fixed-size circular queue implementation.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Design an object store with deduplicationMedium

  This question evaluates a candidate's ability to design scalable, durable object storage systems with deduplication, touching on storage architecture, data modeling, metadata management, consistency, and garbage collection.

  SnowflakeSoftware EngineerSystem DesignTechnical Screen
• Design and Implement a Rate Limiter with an AI Assistant, Then Defend and Test ItMedium

  Design and implement a rate limiter in an AI-assisted coding round: choose and defend an algorithm against its alternatives, direct an AI assistant to write the code, review it and test it. It tests rate-limiting algorithm trade-offs, concurrency, time handling and critical review of generated code.

  SnowflakeMachine Learning EngineerSoftware Engineering FundamentalsOnsite
• Design and validate a cost-sensitive classifierHard

  This question evaluates competence in cost-sensitive binary classification, handling delayed and imbalanced labels, calibration and decision-threshold selection, distributional-drift detection, monitoring, and low-latency deployment within the Machine Learning / Data Science domain.

  SnowflakeData ScientistMachine LearningTechnical Screen
• Design cache for DAG-based query viewsHard

  This question evaluates a candidate's understanding of caching, consistency, versioning, eviction, and update propagation in DAG-based materialized views, testing competencies in distributed systems, data engineering, and storage-hierarchy design.

  SnowflakeSoftware EngineerSystem DesignOnsite
• Design error detection and propagation algorithmsMedium

  This question evaluates algorithm design and complexity-analysis skills across search and graph problems, specifically log search for first-error detection, reachability and failure propagation in directed service dependency graphs, and longest-path reasoning under cycle or DAG assumptions.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Design multi-core service startup schedulerHard

  This question evaluates scheduling and resource-management skills, including DAG dependency handling, concurrency bounding, timeout/retry strategies, observability, and correctness reasoning for service startup orchestration.

  SnowflakeSoftware EngineerSystem DesignOnsite
• Design transactional in-memory key-value storeHard

  This question evaluates understanding of in-memory key–value store semantics, transactional and nested transaction behavior, and practical competencies in hash-based data structures and thread-safety for concurrent access.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen