practice a little every day, paws crossed ♡
Coding & Algorithms 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 2701–2730 of 3276 results
- SnowflakeMediumSoftware EngineerSolve Matrix and Array Distance Problems
Implement a multi-source breadth-first search to find the shortest path from every compute node to its nearest data warehouse in a grid with obstacles.
Coding & AlgorithmsTechnical ScreenGraphBFSMatrix - SnowflakeMediumData ScientistSolve and optimize 3Sum and variants at scale
This question evaluates algorithmic problem-solving skills in array processing, deduplication and combinatorial counting, external-memory and streaming algorithm design, and complexity analysis including integer overflow considerations.
Coding & AlgorithmsOnsite - SnowflakeMediumSoftware EngineerSolve build ordering and expression evaluation
This question evaluates competency in graph algorithms (topological ordering and cycle detection) and in parsing/evaluating arithmetic expressions with correct operator precedence, associativity, unary operators, and 64-bit integer semantics.
Coding & AlgorithmsTechnical Screen - SnowflakeHardSoftware EngineerSolve scheduling and tree path problems
This problem tests your ability to optimize path calculations in a tree by combining depth-first traversal with a greedy or dynamic programming approach to select paths that satisfy specific constraints.
Coding & AlgorithmsTechnical ScreenTreesDynamic ProgrammingRecursion - SnowflakeMediumSoftware EngineerSort an RGB Record Collection In Place
This question tests the ability to partition an array into three distinct groups (Red, Green, Blue) in a single pass using constant extra space, which is a classic application of the Dutch National Flag algorithm.
Coding & AlgorithmsTechnical ScreenSortingTwo PointersIn-place - SnowflakeMediumSoftware EngineerStack with Constant-Time Minimum over a Sequence of Operations
Design a stack that supports push, pop, top and reading its current minimum in constant time, then run it over a sequence of operations and return what the reads produce. Tests data structure design, duplicate minimum values and keeping auxiliary state consistent on every pop.
Coding & AlgorithmsTechnical Screen - SnowflakeMediumSoftware EngineerTransform tree using counterpart subtree sums
This question evaluates proficiency with binary tree algorithms and in-place subtree aggregation, emphasizing traversal strategies, shape verification, and handling subtree sums under linear-time and O(h) space constraints.
Coding & AlgorithmsTechnical Screen - SnowflakeMediumSoftware EngineerTransform tree with subtree sum mapping
Transform tree with subtree sum mapping evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - SnowflakeMediumSoftware EngineerTraverse All Reachable Pages With Parallel BFS
Implement a concurrent breadth-first web crawler that discovers all reachable pages from a start URL. The crawler must fetch pages concurrently while maintaining deterministic level-order output and safely handling cycles and fetch errors.
Coding & AlgorithmsTechnical ScreenBreadth-First SearchConcurrencyGraph - SoFiEasySoftware EngineerCount completed car journeys from sensor logs
This question evaluates stateful event-stream processing and per-entity state management, testing the ability to track and reconcile time-ordered sensor events while handling edge cases like unmatched or spurious events.
Coding & AlgorithmsTechnical Screen - SoFiMediumSoftware EngineerDesign a key-value store with getLast
Design a key-value store with getLast evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - SoFiMediumSoftware EngineerFind Kth Unique Maximum
This problem tests your ability to efficiently manage deduplication and order-statistics using hash maps or sorting techniques while handling multiple input collections.
Coding & AlgorithmsOnsiteHash MapSortingFrequency Count - SoFiEasySoftware EngineerFind Smallest Common Row Value
This question evaluates algorithmic problem-solving skills focused on array processing, intersection across multiple sorted sequences, and time/space complexity analysis.
Coding & AlgorithmsTechnical Screen - SoFiMediumSoftware EngineerFind the second most frequent tag
This question evaluates a candidate's ability to perform frequency analysis and stable tie-breaking on a linear sequence, exercising skills in hashing, counting, and handling edge cases such as equal frequencies.
Coding & AlgorithmsTechnical Screen - SoFiMediumSoftware EngineerFormat words into wrapped/justified lines
This problem tests your ability to implement a greedy word-wrapping algorithm that packs words into lines of a fixed width while managing spacing constraints.
Coding & AlgorithmsTechnical ScreenStringsGreedyArray - SoFiMediumSoftware EngineerImplement a multithreaded task executor with semaphores
This question evaluates understanding of concurrent programming, thread-safety, semaphore-style resource management, exception-safe permit release, and extensible API design, and it falls under the Coding & Algorithms category testing concurrency/multithreading, synchronization primitives, and resource management.
Coding & AlgorithmsTechnical Screen - SoFiMediumSoftware EngineerImplement tree ops and LRU cache
This question evaluates proficiency with tree-based mutable data structures and cache design, specifically maintaining aggregated state in a full binary tree after leaf updates and implementing an LRU cache supporting O(1) get/put operations.
Coding & AlgorithmsOnsite - SoFiEasySoftware EngineerReturn All Nodes Reachable from a Starting Vertex
This problem tests your ability to perform a graph traversal (BFS or DFS) to identify all reachable nodes from a specified starting point in an undirected graph.
Coding & AlgorithmsTechnical ScreenGraphsBFSDFS - SonatusHardSoftware EngineerCompute days until a higher reading
This question evaluates proficiency in array processing and the next-greater-element concept, measuring algorithmic reasoning about sequence traversal, comparisons, and managing time/space trade-offs.
Coding & AlgorithmsTechnical Screen - SpacexMediumSoftware EngineerDynamic Island Counts
Report the exact island count after each land addition by tracking only activated cells and merging distinct neighboring components efficiently.
Coding & AlgorithmsTechnical Screen - SpokeoMediumData ScientistSolve Logic Puzzles: Algorithms and Proofs Required
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Solve Logic Puzzles: Algorithms and Proofs Required states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - SpotifyMediumMachine Learning EngineerJoin Tables and Rank Users
This question evaluates proficiency in SQL and data-engineering skills—specifically joins, aggregation and ranking via window functions, event deduplication, and query performance considerations across analytics tables.
Coding & AlgorithmsOnsite - SpotifyMediumBackend EngineerLongest Contiguous Stretch of Distinct Characters in a String
A Spotify backend technical-screen coding problem: given a string, find the length of the longest contiguous substring in which no character repeats. It tests careful string scanning, linear-time reasoning, and edge cases such as case sensitivity, ties and empty input.
Coding & AlgorithmsTechnical Screen - SquareMediumSoftware EngineerBuild a Trust-Aware BIN Database
Build an in-memory card-prefix database that resolves brand and card type independently across overlapping writes. Practice combining longest-prefix matching with trust and recency rules while preserving omitted fields and supporting heavy lookup traffic.
Coding & AlgorithmsOnsite - SquareHardSoftware EngineerImplement transaction network queries
This question evaluates the ability to model and query dynamic graph connectivity and reachability for pairwise transactions, testing competencies in graph representation, dynamic data structures, and reachability queries within the Coding & Algorithms domain and emphasizing practical application of algorithmic concepts.
Coding & AlgorithmsTechnical Screen - SquareEasySoftware EngineerList the Two-by-Two Blocks Covering Each Black Cell
This problem tests your ability to navigate grid coordinates, implement range boundaries, and perform efficient dictionary-based data collection.
Coding & AlgorithmsTechnical ScreenArraysHash MapsGrid - SquarepointEasySoftware EngineerApply Insert, Update, and Remove Operations to a Keyed Store
Implement an in-memory key-value store processor that executes insert, update, and remove commands with strict handling for missing or duplicate keys, returning the final state in deterministic order.
Coding & AlgorithmsOnsiteHash MapDesignString - SquarepointMediumData ScientistCompute drawdown, profit, and coin change
This question evaluates a candidate's ability to compute financial time-series metrics and apply algorithmic techniques such as array processing and optimization/dynamic programming to identify maximum drawdown and its indices.
Coding & AlgorithmsTechnical Screen - SquarepointMediumData ScientistCount Index Triplets With an Even Product Modulo a Given Number
From a Squarepoint technical screen: count the triplets of distinct positions in an integer array whose three values have an even product, and return the count modulo a given number. It tests efficient counting on large inputs, parity with zero and negative values, and remembering to apply the required modulo.
Coding & AlgorithmsTechnical Screen - SquarepointMediumData ScientistCount Ways to Reach Step n With a Given Set of Step Sizes
From a Squarepoint technical screen: count the ordered sequences of moves that climb exactly n stairs when every move uses a step size from a given set. It tests careful counting of ordered choices, targets that cannot be reached, and the interviewer's follow-up about reducing the extra space the solution uses.
Coding & AlgorithmsTechnical Screen
Snowflake
SoFi
Spotify
Square
Squarepoint