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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 331–360 of 1080 results
- DoorDashMediumSoftware EngineerImplement and compare round-robin and consistent hashing
This question evaluates a candidate's ability to implement and reason about load balancing algorithms (round-robin and consistent hashing), covering competencies in data structures, hashing, concurrency, correctness, and unit testing.
Coding & AlgorithmsOnsite - DoorDashMediumSoftware EngineerImplement image carousel with comments and upvotes
This question evaluates a candidate's ability to design scalable data structures and efficient algorithms for interactive features, including API design, pagination, and consistency/concurrency handling for upvotes and per-image comment threads.
Coding & AlgorithmsOnsite - DoorDashMediumSoftware EngineerImplement round-robin load balancer
This question evaluates a candidate's ability to implement a strict round-robin load balancer with O(1) average operations while handling concurrent nextServer and update calls, health-check-driven skipping, and failure scenarios, testing competencies in data structures, concurrent programming, and fault-tolerant system behavior.
Coding & AlgorithmsOnsite - DoorDashMediumSoftware EngineerSolve tree distance and design file system
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 tree distance and design file system states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - DoorDashMediumSoftware EngineerTrack the First Unique Restaurant in a Stream
This problem tests your ability to maintain stream uniqueness using a combination of a hash map and a doubly linked list to ensure constant-time operations.
Coding & AlgorithmsOnsiteHash MapLinked ListDesign - DropboxMediumSoftware EngineerCompute worst-case guesses for adaptive hangman
This question evaluates algorithmic problem-solving, combinatorial reasoning, and adversarial information-theoretic thinking by requiring modeling of worst-case query strategies for adaptive letter-guessing.
Coding & AlgorithmsOnsite - DropboxMediumSoftware EngineerImplement KV Store and Token Bucket
This problem tests your ability to design a thread-safe in-memory key-value store and implement a rate limiter using the token bucket algorithm.
Coding & AlgorithmsOnsiteConcurrencyData StructuresRate Limiting - DropboxMediumSoftware EngineerImplement feedback for word guessing game
This question evaluates a candidate's ability to implement string-processing, frequency-counting, and membership-validation logic to generate exact and misplaced character matches for a word-guessing game.
Coding & AlgorithmsOnsite - ExpediaMediumSoftware EngineerFind a Canonical Shortest Round Trip Through Flights
Find the shortest directed round trip starting and ending at a given airport, breaking ties lexicographically.
Coding & AlgorithmsOnsitegraphbfsshortest-path - FaireMediumSoftware EngineerPeak number of bikes needed to cover all pre-booked rental intervals
Given every booking for a bike rental service as a start and end time, compute the peak number of bikes in use at the same moment, which is the smallest fleet that serves all bookings. Tests interval-overlap reasoning, half-open boundary handling and an efficient method for up to 100,000 unsorted bookings.
Coding & AlgorithmsOnsite - FigmaMediumSoftware EngineerConvert Leveled Rich-Text Tokens into Nested Lists
Tests parsing a linear sequence of leveled tokens into a hierarchical tree or nested list structure using stack-based tree construction.
Coding & AlgorithmsOnsiteStackTreeAlgorithms - FigmaMediumMachine Learning EngineerImplement Layer History and Grid Counting
This question tests state management through a Command pattern implementation for undo/redo operations and spatial reasoning using depth-first search (DFS) to identify connected components in a 2D grid.
Coding & AlgorithmsOnsiteDesign PatternsStackGraphs - FigmaMediumSoftware EngineerValidate a Balanced INDENT and DEDENT Token Stream
Determine if a sequence of structural tokens maintains valid scoping rules—never closing an un-opened level and closing all levels by the end. Tests single-pass balance checking, edge-case handling for empty streams, and O(1) space optimization.
Coding & AlgorithmsOnsiteStackParsingState Machine - FlexportHardSoftware EngineerIdentify a Target Word with Repeated Minimax Guesses
This problem tests advanced search heuristics and state-space pruning by requiring the implementation of a Wordle-style feedback system that uses a minimax strategy to identify a secret word from a dictionary.
Coding & AlgorithmsOnsiteMinimaxHeuristicsPruning - FlexportHardSoftware EngineerMeasure Meeting Coverage and Required Rooms
This problem tests your ability to manipulate interval data, specifically calculating the total coverage area and finding the maximum concurrency using a sweep-line algorithm.
Coding & AlgorithmsOnsiteSortingSweep-lineIntervals - Fora TravelMediumSoftware EngineerMerge Sorted Arrays
This question evaluates competency in implementing and generalizing merge operations on sorted arrays, exercising algorithmic problem-solving, array manipulation, handling of edge cases (empty arrays, negative numbers, duplicates), and analysis of time and space complexity.
Coding & AlgorithmsOnsite - Freddie MacMediumData ScientistImplement blocked time-series cross-validation
This question evaluates competence in designing panel-aware time-series cross-validation with embargo handling, grouped blocking, deterministic splitting, scalability analysis, and adversarial unit-test design for issues like duplicate timestamps and entity migration.
Coding & AlgorithmsOnsite - FurtheraiMediumMachine Learning EngineerMerge Overlapping Closed Intervals Into a Sorted Disjoint List
A coding question that merges an unsorted list of closed integer intervals into disjoint intervals sorted by start. Intervals that overlap or merely touch at an endpoint must be combined, so it tests exact endpoint semantics, transitive merges, and nested or duplicate intervals.
Coding & AlgorithmsOnsite - GarminMediumSoftware EngineerValue on the Secondary Diagonal of a Center-Out Clockwise Spiral Matrix
A matrix coding question: an odd-sized square matrix is filled with a clockwise spiral that starts at the center cell, and you must return the number on its secondary diagonal a given number of rows above or below the middle row. It tests precise index arithmetic and reasoning about how the spiral grows outward ring by ring.
Coding & AlgorithmsOnsite - GeMediumSoftware EngineerMinimize total distance to a store
This pair of problems evaluates algorithmic problem-solving skills, focusing on spatial optimization with Manhattan distances for grid-based demand aggregation and sequential penalty minimization on binary time-series data, emphasizing reasoning about aggregation and trade-offs.
Coding & AlgorithmsOnsite - GeicoHardSoftware EngineerSolve Refueling and JSON Parsing Tasks
This problem tests greedy strategies for path optimization and recursive descent parsing techniques for custom data structures.
Coding & AlgorithmsOnsiteGreedyPriority QueueRecursive Descent - GeminiMediumData ScientistDetect k events in a sliding window
This question evaluates a candidate's ability to design efficient sliding-window and streaming algorithms for time-series event data, encompassing deduplication, handling bounded out-of-order arrivals and clock skew, distinct-device counting, and meeting specified time and space complexity constraints.
Coding & AlgorithmsOnsite - Gimlet LabsMediumMember of Technical Staff, ML SystemsImplement an LRU Cache
This problem tests the ability to combine a hash map with a doubly linked list to achieve O(1) performance for cache operations.
Coding & AlgorithmsOnsiteHash MapLinked ListCaching - GleanMediumMachine Learning EngineerDecide If a Passenger Can Reach a Station Using Time-Indexed Train Routes and Transfers
Given trains described as time-indexed lists of stations, decide whether a passenger starting at one station at time zero can reach another by riding, waiting and transferring. Tests modeling station and time as search states, handling waits and same-time transfers, and breadth-first search over a time-expanded graph.
Coding & AlgorithmsOnsite - GleanMediumSoftware EngineerDelete the Fewest Parentheses to Balance a String of Only Open and Close Brackets
Given a string of only open and close parentheses, delete the fewest characters so the rest is balanced and return the resulting string, using standard left-to-right matching to define a unique answer. Tests bracket matching, linear-time scanning and careful handling of leftover unmatched characters.
Coding & AlgorithmsOnsite - GleanMediumMachine Learning EngineerFind Earliest Train Route
This question evaluates a candidate's ability to model and search time-dependent transit networks, combining temporal graph reasoning, state-space search, and path reconstruction for itinerary reporting.
Coding & AlgorithmsOnsite - GleanMediumSoftware EngineerFind Which Words From a List Can Be Traced Through Adjacent Cells of a Letter Grid
Given a letter grid and a list of words, return every word that can be spelled by a path of edge-adjacent cells without reusing a cell, sorted lexicographically. Covers the single-word search and its many-words follow-up, and tests backtracking and pruning on a large word list.
Coding & AlgorithmsOnsite - GleanMediumSoftware EngineerFind the k-th Largest Value Across Two Sorted Arrays Without Fully Merging Them
Given two arrays sorted in non-decreasing order and an integer k, return the k-th largest value among all their elements, counting duplicates separately. Tests reasoning about ranks across two sorted sequences, careful handling of empty arrays and duplicates, and moving past a linear scan toward logarithmic time.
Coding & AlgorithmsOnsite - GleanMediumSoftware EngineerGroup Words into Transitive Synonym Sets by Shared Two-Words-Before-and-After Context
Given a list of sentences, treat two words as synonyms when they share the same two words before and two words after, close the relation transitively, and return every synonym group in a canonical sorted order. Tests context hashing, union-find or connected components, and exact output formatting.
Coding & AlgorithmsOnsite - GleanMediumMachine Learning EngineerImplement Rate-Limited Wikipedia Crawler
This question evaluates a candidate's ability to implement a rate-limited web crawler, testing skills in crawl frontier management, prioritization by page-title initial, deduplication, rate limiting, and robust error handling.
Coding & AlgorithmsOnsite
DoorDash
Dropbox
Expedia
Faire
Figma
Freddie Mac
Glean