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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.
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Showing 2491–2520 of 3276 results
- RobloxMediumData ScientistImplement Python Function for Statistical Test P-Values
This question evaluates proficiency in statistical hypothesis testing, p-value interpretation, and implementing distribution-based calculations (Z and Student-t) in code, and it falls under the Coding & Algorithms domain for data scientist roles.
Coding & AlgorithmsTechnical Screen - RobloxMediumSoftware EngineerImplement Sliding-Window Rate Limiter
This problem tests your ability to implement a thread-safe rate limiter using a sliding window algorithm to ensure a user does not exceed a fixed number of requests within a rolling time frame.
Coding & AlgorithmsTechnical ScreenAlgorithmsData StructuresRate Limiting - RobloxMediumSoftware EngineerImplement a Log Rate Limiter
This problem tests your ability to design a thread-safe, time-windowed rate limiter using efficient data structures to track event timestamps.
Coding & AlgorithmsOnsiteHash TableDesignConcurrency - RobloxMediumSoftware EngineerImplement a sliding-window rate limiter
Evaluates the candidate's ability to design and implement an in-memory sliding-window rate limiter enforcing per-user and per-game constraints, focusing on correct request-acceptance semantics and efficient timestamp eviction; Category/domain: Coding & Algorithms; Level of abstraction: component-level algorithm and data-structure implementation.
Coding & AlgorithmsOnsite - RobloxEasyData ScientistImplement four DS coding tasks
This multi-part question evaluates a data scientist's competencies in statistical inference (sample size and z-test calculations), causal inference and parallel-trends validation (difference-in-differences), Bayesian probability updating, and interpretable supervised learning feature importance, all framed as coding tasks.
Coding & AlgorithmsOnline Assessment - RobloxMediumSoftware EngineerImplement queue-based rate limiter with multi-key limits
This question evaluates implementation and design skills around rate limiting, including rolling-window counters, multi-key constraints, and atomic updates, and falls under the Coding & Algorithms domain focused on practical application of algorithms and data structures.
Coding & AlgorithmsOnsite - RobloxEasyMachine Learning EngineerImplement recent-requests counter
This question evaluates a candidate's ability to design efficient in-memory data structures and manage time-windowed event counting, testing algorithmic reasoning and performance optimization for high-throughput services.
Coding & AlgorithmsTechnical Screen - RobloxMediumData ScientistImplement streaming CTR with deduplication
This question evaluates streaming data-processing and algorithmic design skills, specifically time-windowed aggregation, click deduplication, late-event handling, state management, and selection of data structures for per-campaign CTR computation.
Coding & AlgorithmsTechnical Screen - RobloxMediumMachine Learning EngineerLevel-Ordered Dependency Build Order
This problem tests your ability to perform a Kahn’s algorithm-based topological sort while grouping tasks into parallelizable layers, ensuring cycle detection and dependency validation.
Coding & AlgorithmsTechnical ScreenGraphBFSTopological Sort - RobloxMediumSoftware EngineerMatch-3 Grid: Find Horizontal and Vertical Runs, Then Clear and Drop Cells
A two-part grid problem modeled on a Match-3 game: report every horizontal and vertical run of three or more equal values in a fixed scan order, then clear the matched cells and let the remaining values in each column fall to the bottom. It tests precise run detection, ordering rules and grid simulation.
Coding & AlgorithmsTechnical Screen - RobloxMediumSoftware EngineerNumber Line Obstacles: Check Whether a Centered Block Can Be Built
Process operations on an infinite integer number line that either place an obstacle or ask whether a block centered at a point, reaching a given distance in each direction, is free of obstacles, and return the answers as a binary string. It tests efficient online range queries over large, sparse coordinates.
Coding & AlgorithmsOnline Assessment - RobloxMediumData ScientistOptimize assembly-line scheduling with changeovers
This question evaluates combinatorial optimization and scheduling competencies, specifically reasoning about NP-hardness, sequence-dependent setup times, precedence and downtime constraints, and designing exact and heuristic solvers for makespan minimization.
Coding & AlgorithmsOnline Assessment - RobloxMediumData ScientistOptimize bread-factory pipeline for max profit
This question evaluates skills in combinatorial optimization, budgeted resource allocation, bottleneck throughput modeling, and algorithm design with cost amortization for maximizing profit under constraints.
Coding & AlgorithmsOnsite - RobloxMediumSoftware EngineerRandomly partition array into k segments
This question evaluates algorithm design, randomization techniques, and time/space complexity analysis within the Coding & Algorithms domain, focusing on partitioning an array into random non-empty segments.
Coding & AlgorithmsTechnical Screen - RobloxHardSoftware EngineerRank queries by prefix, frequency, and time
This question evaluates understanding of string processing, frequency aggregation, earliest-timestamp tracking, and efficient prefix-based retrieval for large datasets.
Coding & AlgorithmsTechnical Screen - RobloxMediumSoftware EngineerSimulate robot path and detect boundedness
This question evaluates the ability to simulate iterative movement and reason about repeated state transformations, testing competencies in algorithm design, cycle detection, and geometric reasoning; it falls under the Coding & Algorithms category.
Coding & AlgorithmsOnsite - RobloxMediumSoftware EngineerTrail Campsite Clearance: Online Pin and Range-Empty Queries
Process a stream of events that drop hazard pins at integer mile markers or ask whether a campsite centered at a marker with a given radius would be hazard-free, returning the answers as a string. Tests sparse-coordinate range counting with binary search and a Fenwick tree.
Coding & AlgorithmsOnline Assessmentfenwick-treecoordinate-compressionbinary-search - RogoMediumMachine Learning EngineerInfer the Smallest Valid Character Order from Sorted Password Hints
This problem tests your ability to model dependency constraints using a Directed Acyclic Graph (DAG) and apply Kahn's algorithm or DFS-based topological sorting to resolve ordering dependencies.
Coding & AlgorithmsOnsiteGraphTopological SortPriority Queue - RoktEasySoftware EngineerImplement basic calculator with four operations
This question evaluates a candidate's ability to parse and evaluate arithmetic expressions, correctly apply operator precedence and left-to-right associativity, and handle integer arithmetic details such as truncating division, whitespace, and multi-digit numbers, and is commonly asked to assess implementation-level parsing and algorithmic reasoning. The category is Coding & Algorithms and the level of abstraction is practical application, focusing on coding an efficient evaluator that balances time and space constraints rather than purely conceptual theory.
Coding & AlgorithmsOnsite - RokuMediumSoftware EngineerCompute longest common subsequence length
This question tests the ability to solve the Longest Common Subsequence (LCS) problem using dynamic programming to optimize overlapping subproblems.
Coding & AlgorithmsOnsiteDynamic ProgrammingStringsAlgorithms - RubrikHardSoftware EngineerFind largest connected group of overlapping intervals
This question evaluates understanding of interval overlap modeling, graph connectivity, and algorithmic efficiency by requiring mapping time intervals to an undirected communication graph and identifying its largest connected component.
Coding & AlgorithmsOnline Assessment - RubrikHardSoftware EngineerValidate BFS order queries on a tree
This question evaluates understanding of BFS traversal, tree graph representation, and the ability to reason about allowable dequeue/enqueue orderings in a FIFO queue.
Coding & AlgorithmsOnline Assessment - RunloopMediumSoftware EngineerReturn a Topological Order or Detect a Cycle
This problem tests your ability to implement Kahn's algorithm for topological sorting while incorporating a priority-based tie-breaking mechanism to ensure deterministic output.
Coding & AlgorithmsTechnical ScreenGraphTopological SortHeap - SIG (Susquehanna)MediumData ScientistCompute bus-on-time and dice-sum probabilities
This problem tests your ability to calculate probabilities involving continuous uniform distributions and discrete combinations of independent events.
Coding & AlgorithmsHR ScreenProbabilityCombinatoricsUniform Distribution - SIG (Susquehanna)MediumSoftware EngineerCount Equal-Difference Triples After Each Add or Remove-All Operation
Process a stream of add-one and remove-all operations on a multiset and report, after each operation, how many element triples form an arithmetic progression with a fixed positive difference. It tests efficient incremental updates, correct treatment of duplicate occurrences, and counts that exceed the 32-bit range.
Coding & AlgorithmsOnline Assessment - SIG (Susquehanna)MediumSoftware EngineerCount subarrays with odd zero count
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Count subarrays with odd zero count states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnline Assessment - SIG (Susquehanna)EasySoftware EngineerFind Company Tickers Mentioned in a News Headline
Implement a headline scanner that identifies mentioned company names using whole-word matching and returns their unique stock tickers in the order specified by the input mapping.
Coding & AlgorithmsOnsiteStringsHash TableTrie - SIG (Susquehanna)MediumSoftware EngineerRotate a Square Matrix Clockwise While Both Diagonals Stay Fixed
Rotate every element of a square matrix that lies off both diagonals by 90 degrees clockwise a given number of times, leaving the main-diagonal and anti-diagonal values in place. It tests precise index mapping, handling of odd and even matrix sizes, and bug-free simulation under timed assessment conditions.
Coding & AlgorithmsOnline Assessment - SIG (Susquehanna)MediumSoftware EngineerSolve theatre seating and ticker extraction
This question evaluates algorithmic problem-solving skills across two areas: efficient seat-allocation and interval occupancy reasoning for grouping in a constrained seating layout, and robust string processing with phrase-based, case-insensitive matching and mapping to ticker identifiers.
Coding & AlgorithmsOnsite - SalesforceMediumSoftware EngineerBinary Tree Path Sum
Determine if a binary tree contains a root-to-leaf path whose node values add up to a given target sum.
Coding & AlgorithmsOnsiteBinary TreeDFSBFS
Roblox
Rubrik
SIG (Susquehanna)
Salesforce