Snowflake interview questions

Showing 91–120 of 130 results

• Implement and Test a Sliding-Window Rate LimiterMedium

  This problem tests your ability to implement an efficient sliding-window algorithm and design a robust testing strategy for a stateful component.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsOnsite
• Implement course scheduling and rate limiter analysisHard

  This combined question evaluates proficiency in graph-based dependency reasoning (cycle detection and course scheduling) and time-series request processing (rate-limiter behavior and sliding-window request counting) within the Coding & Algorithms domain.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Implement crawler and bracket validatorMedium

  This question evaluates competencies in web crawling and string validation, covering graph traversal and cycle avoidance with domain filtering for crawl discovery, and delimiter matching with error indexing for multi-type bracket validation.

  SnowflakeSoftware EngineerCoding & AlgorithmsOnsite
• Implement topological sort and tree boundary traversalMedium

  These tasks evaluate core competencies in directed graph algorithms (topological ordering and cycle detection) and binary tree traversals (boundary identification and leaf enumeration), testing understanding of dependency modeling and traversal patterns.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• In-Memory Key-Value Store with Constant-Time Nested TransactionsMedium

  Build an in-memory key-value store with get, set and delete plus nested begin, commit and rollback, aiming for constant-time operations. Follow-ups extend it to concurrent threads, keys with a time to live, and reads of a key's value at an earlier point in time.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• Lead innovation and automate a critical processMedium

  This question evaluates leadership and technical program management competencies for a Data Scientist, including end-to-end innovation, cross-functional stakeholder alignment, risk identification and mitigation, trade-off rationale, measurable impact assessment, and process automation architecture and maintainability.

  SnowflakeData ScientistBehavioral & LeadershipTechnical Screen
• List the Nodes on the Path Between Two Nodes of a Binary TreeMedium

  Given a binary tree stored as child-index arrays and two node indices, return the nodes on the unique path between them, from the first node to the second. It tests parent tracking, ancestor reasoning and handling cases where one node lies above the other.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Maximize revenue by choosing one query typeHard

  This problem tests greedy optimization and modular arithmetic skills to determine the most profitable query strategy given a limited time window.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Minimize coins with overpay and changeHard

  This problem tests your ability to optimize combinatorial decisions under constraints by identifying a greedy approach with a fallback to search or dynamic programming.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Minimum Months to Finish All Courses with Durations and Unlimited ParallelismMedium

  Courses take different numbers of months, some must finish before others start, and any number can run in parallel; return the minimum time to finish them all. It tests longest-path reasoning on a directed acyclic graph processed in topological order.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Minimum Node Deletions to Bring an N-ary Tree's Height Within kMedium

  Given an N-ary tree as a parent array and a limit k, find the fewest non-root nodes to delete, promoting each deleted node's children to its nearest surviving ancestor, so that the tree's height is at most k. It tests reasoning about root-to-leaf paths and choosing deletions that shorten many paths at once.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Minimum Prunes to Bring a Filesystem Tree's Depth Under a LimitMedium

  Given a directory tree where deleting a node reattaches its children to its own parent, find the minimum number of deletions needed to bring the deepest root-to-leaf path down to a given limit. Tests a budget-passing tree DP where deleting a node changes how much depth its children inherit.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Most Frequent k Words or Bestselling Titles with Alphabetical Tie-BreaksMedium

  Given a list of items such as trending words or bestselling book titles and a number k, return the k most frequent items ordered by count, with ties broken alphabetically. It tests frequency counting, sorting with a compound key and heap-based selection.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Most Meetings You Can Attend When Each Takes One Day Within Its RangeMedium

  Each meeting can be attended on any single day within its range, and only one meeting fits on each day; return the largest number of meetings you can attend. It tests interval scheduling reasoning and an exchange argument for why a local choice stays optimal.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Multiset with O(1) Insert, Remove, and Count-Weighted Random PickMedium

  Design a collection of integers that allows duplicates and supports insert, remove and a random pick weighted by occurrence count, each in average constant time. Tests array and hash map bookkeeping, careful handling of moved elements during removal, and how to test randomized behavior.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsOnsite
• Multithreaded Web Crawler with Retries for a Failing Fetch APIMedium

  Write a web crawler that visits every page reachable from a start URL through a slow link-fetching API, first with BFS or DFS, then with multiple threads, then with retries when the API fails. It tests visited-set safety, termination detection, backoff and failure reporting.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• N-ary Tree Height After Deleting Nodes and Reattaching Their ChildrenMedium

  Given an N-ary tree as a parent array and a set of nodes to delete, move each deleted node's children up to its nearest surviving ancestor and report the height of the resulting tree. Tests building a tree from parent links, reasoning about cascading deletions, and computing depths on a tree that can be a path of 100,000 nodes.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Present Your Infrastructure and Platform ExperienceMedium

  Assesses your ability to articulate end-to-end platform engineering achievements, architectural trade-offs, and operational ownership in a structured, impactful manner.

  SnowflakeDevOps EngineerBehavioral & LeadershipHR Screen
• Print an Org Chart as a Depth-Ordered List from Supervisor PairsMedium

  Given a flat list of (person, supervisor) ID pairs, reconstruct the organization as a forest rooted at whoever has no supervisor, then emit a deterministic preorder listing of (id, depth). Tests root detection, building ordered adjacency lists, and careful DFS ordering.

  SnowflakeSoftware EngineerCoding & AlgorithmsOnsite
• Propagate Permission Letters Through a DAG Using Each Node's Final StateMedium

  Given a directed acyclic graph in which each node grants and revokes letter permissions, compute every node's final set of letters when each node passes only its final state to its children. Tests topological processing, set propagation over multiple parents, and letters that descendants grant again after an ancestor revokes them.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Query Unique and Most-Frequent Keys in a Recent Event WindowMedium

  Design an in-memory event tracker that maintains the most recent m arrivals from a timestamped stream and efficiently queries distinct key counts and top-frequency keys above a cutoff timestamp.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Query seven-day conversion with windows and dedupeMedium

  This question evaluates proficiency in time-windowed aggregations, event deduplication, and window-function–based user-level analytics across SQL and Pandas workflows.

  SnowflakeData ScientistData Manipulation (SQL/Python)Technical Screen
• Rate Limiter with Tiers, Runtime Config Changes and Multiple RulesMedium

  Implement a rate limiter using a token bucket or sliding window, then support client tiers whose limits change while the service runs, several rules checked on one request, and deterministic tests with a mock clock. It tests algorithm choice, safe configuration swaps and thread-safe all-or-nothing checks.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• Replay Ops on a Freezer-Probe Stack That Tracks Its Minimum in O(1)Medium

  Replay a sequence of push/pop/peek/min-read operations on a stack of freezer temperature readings and return what each read produces, where reading the current minimum must be as fast as pushing or popping. Tests pairing a stack with running-minimum bookkeeping that stays correct through duplicate minimums and repeated pops.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Return the Prerequisite Route for a Target CourseMedium

  Find a deterministic, lexicographically smallest topological order of all direct and indirect prerequisites for a specific target course while ignoring cycles outside the target's dependency subgraph.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Reverse a Character Array In Place with Constant Extra MemoryMedium

  Reverse a string given as an array of characters in place, using only constant extra memory, and return the same list. A short coding warm-up that tests index handling, swapping elements and odd and even lengths without building a copy.

  SnowflakeSoftware EngineerCoding & AlgorithmsTechnical Screen
• Schedule prerequisite classes with retakesEasy

  This problem tests your ability to model dependencies using a Directed Acyclic Graph (DAG) and perform a topological sort while accounting for re-take conditions.

  SnowflakeSoftware EngineerCoding & AlgorithmsOnsite
• Serialize a List of Arbitrary Strings into One String and Back, Then Compare SchemesMedium

  A two-part coding question that asks you to pack a list of arbitrary strings, which may contain any character, into a single string and rebuild the identical list from that string alone. It tests unambiguous format design, empty-string edge cases, linear-time parsing and a reasoned comparison of alternative encoding schemes.

  SnowflakeSoftware EngineerSoftware Engineering FundamentalsOnsite
• Serialize and deserialize a dictionary trieMedium

  Snowflake software-engineer onsite coding question: design a compact, robust wire format to serialize and deserialize a dictionary trie. Covers DFS vs BFS encodings, delimiter vs length-prefix framing and escaping, explicit end-of-word markers, streaming, malformed/partial-input handling, forward/backward compatibility, Unicode, compression, memory limits, and O(N) complexity.

  SnowflakeSoftware EngineerCoding & AlgorithmsOnsite
• Solve Array Distance and Wiki NavigationMedium

  This question evaluates array-processing and graph-algorithm skills, specifically minimum-distance computation between marked elements in a one-dimensional array and shortest-path navigation in a directed link graph, plus edge-case reasoning and test-case design.

  SnowflakeSoftware EngineerCoding & AlgorithmsOnline Assessment