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 1051–1080 of 1080 results
- WaymoMediumSoftware EngineerInsert +, -, * and Parentheses Between Ordered Numbers to Reach a Target
Given numbers in a fixed order and a target, insert +, - or * between them and add parentheses to reach the target, returning the lexicographically smallest fully parenthesized expression or an empty string. Starts with three numbers and generalizes to n, testing exhaustive search over expression trees.
Coding & AlgorithmsOnsite - WaymoMediumSite Reliability EngineerIs the Segment From 0 to 50 Fully Contaminated After Each Landing Point?
Points land one at a time on the segment from 0 to 50, each contaminating an interval of length 1 around it; after each landing, report whether the whole segment is contaminated. Tests interval union maintenance, exact boundary handling and efficient updates.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerLowest Horizontal Cut That Splits Square Cakes Into Equal Total Areas
Square cakes sit on a table with sides parallel to its edges; find the lowest horizontal cut line that splits the total cake area equally, returned as an exact fraction. Tests sweeping over heights, piecewise-linear area accumulation and exact arithmetic.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerMinimize Total Grid Distance to Every Building
Find an empty land cell in a 2D grid that minimizes the sum of shortest travel distances to all buildings without traversing through obstacles or other buildings.
Coding & AlgorithmsOnsiteBreadth-First SearchMatrixShortest Path - WaymoMediumMachine Learning EngineerReturn All Words Matching Each Prefix From a Word List
Build a structure over a word list that answers prefix queries, returning every distinct word that starts with each prefix in lexicographic order. Tests prefix-tree design, deduplication, and answering many queries without rescanning the whole list.
Coding & AlgorithmsOnsite - WaymoMediumSoftware EngineerSort the Results of Applying a Quadratic Function to a Sorted Array
Apply the quadratic function a*x*x + b*x + c to every element of a sorted integer array and return the results in sorted order, where a may be negative or zero. Tests reasoning about the parabola's shape and merging values from both ends in linear time.
Coding & AlgorithmsOnsite - WorkdayMediumSoftware EngineerBuild a Fuzzy Keyword Index
This problem tests your ability to design an efficient data structure for performing fuzzy keyword lookups using edit distance constraints on a static corpus of strings.
Coding & AlgorithmsOnsiteStringsTrieHash Map - Zest AIHardData ScientistCompute tree depth and meeting rooms
This question evaluates skills in tree traversal and recursion for computing maximum depth of a binary tree, alongside interval scheduling and resource allocation for determining the minimum number of meeting rooms, testing reasoning about data structures such as trees and interval endpoints.
Coding & AlgorithmsOnsite - ZipHQMediumSoftware EngineerFind flush and straight groups in cards
This question evaluates array and string manipulation, grouping and sequence-detection competencies, specifically handling same-rank aggregation and same-suit consecutive runs with overlap and maximality considerations.
Coding & AlgorithmsOnsite - ZiprecruiterMediumSoftware EngineerDesign a voting counter for restaurants
This question tests the ability to manage real-time updates to counters using hash maps and to implement a deterministic sorting logic for ranking items with tie-breaking rules.
Coding & AlgorithmsOnsiteHash MapSystem DesignSorting - ZooxHardSoftware EngineerCan a Car Meet a Truck?
This problem tests your ability to determine if two entities moving on a 2D grid can ever occupy the same coordinate at the same time, using interval arithmetic and pathfinding logic.
Coding & AlgorithmsOnsiteGeometryAlgorithmsSimulation - ZooxEasyData ScientistChoose fastest way to transfer 2 TB
This question evaluates a candidate's ability to compare large-scale data transfer methods and reason about trade-offs among bandwidth, latency, security, cost, and logistics, reflecting competency in data engineering, networking, and systems design.
Coding & AlgorithmsOnsite - ZooxMediumData EngineerWrite SQL revenue and anomaly queries
This question evaluates SQL proficiency and data engineering competency in revenue aggregation, netting purchases and refunds, joining transaction and vendor tables, and designing data quality and anomaly detection checks.
Coding & AlgorithmsOnsite - eBayMediumSoftware EngineerCompute the Wait for a Warmer Day
This problem tests your ability to efficiently find the distance to the next greater element in an array, typically requiring an O(n) approach using a monotonic stack.
Coding & AlgorithmsOnsiteArraysStackMonotonic Stack - eBayMediumSoftware EngineerFind the Container with the Most Water
This problem tests your ability to optimize an O(n^2) brute-force approach into an O(n) two-pointer solution by leveraging geometric constraints.
Coding & AlgorithmsOnsiteArraysTwo PointersGreedy - eBayHardSoftware EngineerFind top co-viewed products
This question evaluates algorithmic problem-solving and implementation skills in the Coding & Algorithms domain, including frequency aggregation, ordering with tie-breakers, and efficient data-structure use for session-based recommendation counting.
Coding & AlgorithmsOnsite - eBayMediumSoftware EngineerPass functions and analyze basic data structures
This question evaluates proficiency with higher-order functions, passing functions or delegates, closures, and reasoning about side effects, alongside the ability to analyze fundamental data structures and their performance characteristics.
Coding & AlgorithmsOnsite - eBayMediumSoftware EngineerSolve Dependency, Prefix, and Cache Problems
This set of problems evaluates graph algorithms for dependency and cycle detection, efficient data structure design for prefix-based word storage, and cache eviction policy implementation, assessing skills in algorithmic analysis, data structures, and time/space complexity within the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - xAIMediumSoftware EngineerCompute total active time per Twitter Space
This problem tests your ability to process chronological event streams to calculate overlapping or continuous active intervals and aggregate durations per category.
Coding & AlgorithmsOnsiteSortingHash MapData Processing - xAIHardMachine Learning EngineerConstant-Time Insert, Remove, and Uniform Random Sampling
This question evaluates the ability to design a data structure that supports constant-time insertions, removals, and uniform random sampling, testing concepts such as hashing, indexed storage, and randomized selection within the coding and algorithms domain.
Coding & AlgorithmsOnsite - xAIMediumSoftware EngineerDesign a Least Frequently Used (LFU) Cache with O(1) Operations
This question evaluates understanding of data structures and algorithm design for implementing a Least Frequently Used (LFU) cache with O(1) get and put operations, emphasizing frequency tracking and least-recently-used tie-breaking.
Coding & AlgorithmsOnsite - xAIHardMachine Learning EngineerGreedy Longest-Match Tokenizer for an LLM Data Pipeline
This question evaluates understanding of string-processing and greedy maximal-munch tokenization, as well as competency in designing efficient prefix-matching data structures and handling large-scale text preprocessing for LLM pipelines.
Coding & AlgorithmsOnsite - xAIMediumSoftware EngineerImplement a parallelized sort
This problem tests your ability to implement a parallelized version of Merge Sort using threads or a thread pool, focusing on partitioning, synchronization, and managing recursion depth.
Coding & AlgorithmsOnsiteAlgorithmsConcurrencyMerge Sort - xAIMediumMachine Learning EngineerImplement dynamic batching for token decoding
This question evaluates dynamic batching, per-request state management, and sequence-decoding correctness for language-model inference, including handling stop conditions, max-token limits, and maintaining a correct slot-to-request mapping.
Coding & AlgorithmsOnsite - xAIEasySoftware EngineerIn-Memory Key-Value Database with Nested Transactions
This question evaluates understanding of in-memory data structures, transactional semantics (including nested transactions), and algorithmic complexity for implementing a key-value store that supports efficient GET/SET and rollback/commit operations.
Coding & AlgorithmsOnsite - xAIMediumSoftware EngineerMinimum Time to Run All Jobs with a Cooldown Between Identical Jobs
This question evaluates understanding of scheduling constraints, frequency analysis, and time-complexity reasoning required to minimize total execution time under per-type cooldown restrictions.
Coding & AlgorithmsOnsite - xAIEasySoftware EngineerPhone Keypad Predictive Text Suggestions
This question evaluates understanding of string-to-digit encoding, prefix-based retrieval, and efficient preprocessing for fast query-time lookup in large dictionaries.
Coding & AlgorithmsOnsite - xAIMediumSoftware EngineerSort a Large Array Using Multiple Threads
This question evaluates understanding of concurrent programming, parallel algorithm design, sorting algorithms, and merging techniques under multi-threaded execution, focusing on thread-safety, deterministic correctness despite scheduling variability, and performance trade-offs.
Coding & AlgorithmsOnsite - xAIMediumSoftware EngineerVersioned Key-Value Store with Nested Transactions (Begin, Commit, Rollback)
This question evaluates understanding of transactional state management, nested transactions, visibility semantics for set/delete operations, and efficient in-memory data-structure manipulation.
Coding & AlgorithmsOnsite - xAIMediumSoftware EngineerWeighted LRU Cache: Capacity Counted by Item Quantity
This question evaluates understanding of cache design and LRU eviction semantics with weighted resource accounting, plus data-structure and amortized-complexity reasoning needed to support O(1) average-time operations.
Coding & AlgorithmsOnsite
Waymo
ZipHQ
Zoox
xAI