Snowflake two coding screens interview

Questions Snowflake asks in this round 34

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  Effective privileges in a role hierarchy with allow and disallow listsCodingYou are building the access-control layer of a data platform. Every role has: - allowed: privileges granted directly to the role - disallowed: privileges explicitly taken away…

  Last asked Sep 2026Were you asked this too?
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  Encode and decode strings with length prefixes and count codesCodingSerialize a list of arbitrary strings into one string and back without ambiguity. A second variant decodes a compact code where some letters are written as two digits with a…

  Last asked Sep 2026Were you asked this too?
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  Minimum buses to run a timetableCodingA bus depot has a timetable of trips, each with a departure time and an arrival time. A bus can take a new trip once it has arrived from its previous one. Return the fewest buses…

  Last asked Sep 2026Were you asked this too?
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  Fewest clicks between two wiki pagesCodingWiki pages link to other pages. Given a start page and a target page, return the fewest clicks needed to get from one to the other, or report that the target can't be reached. You…

  Last asked Sep 2026Were you asked this too?
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  Concurrent same-host web crawlerCodingImplement a web crawler that finds every page reachable from a start URL on the same host, and fetches pages concurrently. You are given a blocking helper: Write: python def…

  Last asked Jul 2026Were you asked this too?
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  Boundary of a binary treeCodingWalk around the outside of a binary tree starting at the root: down the left edge, along the leaves from left to right, then up the right edge. The nodes you pass form the…

  Last asked Jul 2026Were you asked this too?
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  Minimum distance between two nodes in an N-ary treeCodingYou are given the root of an N-ary tree. Every node has an integer val, unique within the tree, and a list children of its direct children. There are no parent pointers…

  Last asked Feb 2026Were you asked this too?
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  Evaluate an arithmetic expression with variablesCodingEvaluate an arithmetic expression string with numbers, +, -, , /, parentheses and variable names whose values are given in a map. Respect precedence and parentheses, and decide…

  Possibly retiredWere you asked this too?
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  Fill a second tree with subtree sums of the firstCodingYou get the roots of two complete binary trees with exactly the same shape. For every node of the second tree, set its value to the sum of the subtree rooted at the matching node…

  Possibly retiredWere you asked this too?
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  Find the first error in a log, then trace failures through dependenciesCoding1. A service's log lines are tagged Info, Warn or Error. Once the first Error appears the service is down, so every later line is an Error too, and the line just before the first…

  Possibly retiredWere you asked this too?
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  Project deep dive: present a project you ledBehavioralPresent a project you led in about 20 minutes: context, your role, the architecture, three hard trade-offs, metrics, cost and return, and what you would change. Then take 25…

  Last asked Sep 2026Were you asked this too?
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  Design a control plane for cloud clusters with host health checksSystem designDesign the management layer of a cloud platform that runs clusters of hosts (VMs or physical machines). It takes requests to create, resize and change clusters, decides which…

  Last asked Sep 2026Were you asked this too?
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  Throne inheritance without an initial kingCodingModel a royal family's line of succession: people are born to parents, people die, and you return the current order of inheritance (a pre-order walk of the family tree that skips…

  Last asked Sep 2026Were you asked this too?
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  Design an interactive query notebookSystem designDesign a notebook product where users write queries in cells, run them interactively against a data warehouse, and see results stream back into the notebook. Cover the session…

  Last asked Aug 2026Were you asked this too?
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  Copy list with random pointerCodingEach node of a singly linked list has a next pointer and a random pointer that may point to any node in the list or to nothing. Return a deep copy of the list in which no pointer…

  Last asked Aug 2026Were you asked this too?
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  Tiered rate limiter with limits that change at runtimeCodingBuild a rate-limiting service in Python. Each client belongs to a tier (for example free, pro, enterprise), and each tier has its own limit. A request arrives with a client id…

  Last asked Aug 2026Were you asked this too?
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  Arrow-key controlled kanban board in ReactCodingBuild a kanban board in React with columns of cards. A card can be selected, and the arrow keys move the selection or the selected card between positions and columns. Keep the…

  Last asked Aug 2026Were you asked this too?
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  Design calendar front-end state for recurring eventsSystem designDesign the client-side state for a calendar app that supports recurring events. Cover how recurrence rules are stored versus expanded into visible occurrences, how a single…

  Last asked Aug 2026Were you asked this too?
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  Unique and most frequent keys in a recent time windowCodingEvents arrive with a key and a timestamp. Build a structure that, for the most recent window of time, answers which keys appeared exactly once and which key appeared most often…

  Last asked Aug 2026Were you asked this too?
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  Design a nearby points-of-interest serviceSystem designGiven a user's location, return the closest restaurants, shops and other places of interest within a radius, fast, for a read-heavy global audience.

  Last asked Jul 2026Were you asked this too?
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  Find every set in a hand of Set cardsCodingEach card in the game Set has four attributes (color, shape, number, shading), and each attribute takes one of three values, so a card is four numbers from 0 to 2. Three cards…

  Last asked Jul 2026Were you asked this too?
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  Design an audit log serviceSystem designDesign a service that records who did what to which resource across a platform, for security and compliance. Cover the event schema, how producers write reliably without slowing…

  Last asked Jun 2026Were you asked this too?
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  Sort colors in placeCodingYou get an array of records, each tagged red, green or blue. Sort it in place so all reds come first, then greens, then blues, in one pass and constant extra space (the Dutch…

  Last asked Jun 2026Were you asked this too?
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  Design a system that turns Jira tickets into pull requestsAI systemDesign an automated system that picks up a Jira ticket, uses an AI coding agent to write the change in the right repository, and opens a pull request for review. Cover how tickets…

  Last asked Jun 2026Were you asked this too?
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  Implement a JSON parserCodingWrite a parser that turns a JSON string into native values: objects, arrays, strings with escapes, numbers, true, false and null. Use a recursive-descent design, skip whitespace…

  Last asked Jun 2026Were you asked this too?
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  Three-color map coloringCodingYou are given a map as a list of location names, locations, and a list of pairs, adjacencies. Each pair a, b means locations a and b share a border. Implement colormap(locations…

  Last asked Jun 2026Were you asked this too?
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  Insert documents and check them against boolean predicatesCodingBuild a small server with two calls: insertdoc(filename) stores a document, and checkcontains(filename, predicate) answers whether the document satisfies a predicate over terms…

  Last asked Apr 2026Were you asked this too?
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  Fewest coins when change can be given backCodingYou need to pay an amount using coins of given denominations, but you may overpay and receive change back in the same denominations. Return the fewest coins that change hands in…

  Last asked Mar 2026Were you asked this too?
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  Shortest path between two cells in a gridCodingGiven a grid with open and blocked cells, return the length of the shortest path from a start cell to a target cell moving up, down, left and right. A follow-up changes the…

  Last asked Feb 2026Were you asked this too?
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  Pick the most profitable repeated queryCodingA data warehouse has a time budget of k minutes and n query types. Query type i takes timesi minutes per run and earns profitsi per completed run. You must commit to one query…

  Last asked Jan 2026Were you asked this too?
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  Implement an event emitterCodingImplement an event emitter class: on(event, handler), off(event, handler), once(event, handler) and emit(event, ...args). Handlers run in the order they were added. Handle a…

  Last asked Jan 2026Were you asked this too?
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  React class components, lifecycle methods and hooksCodingExplain how React class components work and the order of their lifecycle methods (mount, update, unmount), then how the same behavior is written with hooks: useState, useEffect…

  Last asked Jan 2026Were you asked this too?
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  Validate a tic-tac-toe board stateCodingGiven a tic-tac-toe board in the middle or at the end of a game, decide whether it could have been reached by legal play: X moves first, players alternate, and nobody moves after…

  Last asked Dec 2025Were you asked this too?
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  Remove deleted folders and their descendants from a path listCodingYou get a list of hierarchical paths such as California, California/San Francisco and California/San Francisco/7th Street, and a list of paths to delete. Deleting a path removes…

  Possibly retiredWere you asked this too?