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 781–810 of 3276 results
- CitadelMediumSoftware EngineerReturn nodes on a tree diameter path
This problem tests your ability to perform a two-pass Breadth-First Search (BFS) or Depth-First Search (DFS) on an undirected tree to find the longest path and reconstruct the sequence of nodes that form it.
Coding & AlgorithmsTechnical ScreenTreesGraph TheoryBFS - CitadelMediumSoftware EngineerSimulate 2048 and pack board into uint64
This question evaluates proficiency in implementing deterministic game-state logic and compact binary representations, specifically array manipulation and merge semantics for 2048 slide operations plus bit-level packing/unpacking of 4-bit exponent fields.
Coding & AlgorithmsOnsite - CitadelHardData ScientistSort a nearly sorted array
This question evaluates algorithmic problem-solving skills, specifically understanding sorting under constrained inputs and rigorous time and space complexity analysis.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerTop-K Largest Elements in Every Sliding Window
Design an algorithm to maintain and extract the top-K largest elements in descending order for each sliding window of size W across an array.
Coding & AlgorithmsTechnical ScreenSliding WindowHeapOrdered Set - CitadelMediumData ScientistUpdate No-Intercept Regression Slopes Across Batches
Compute cumulative no-intercept regression slopes as paired data arrives in batches. Reuse running cross-products and sums of squares instead of refitting all historical rows.
Coding & AlgorithmsTechnical Screen - CitiMediumSoftware EngineerExplain data structure fundamentals
This question evaluates understanding of data structure fundamentals, specifically hash map internals (hashing, collision resolution strategies, load factor, and resizing), time complexity analysis for search/insert/delete, contrasts between arrays and linked lists for random access and insertion, and typical use cases and complexities for stacks versus queues. It is commonly asked in technical interviews to assess algorithmic thinking and the ability to reason about performance trade-offs and appropriate data structure selection; domain: Coding & Algorithms; level: tests both conceptual understanding and practical application.
Coding & AlgorithmsOnsite - ClickupMediumSoftware EngineerProcess document edit events
This question evaluates implementing and manipulating a line-based document through sequential event processing, emphasizing array/list operations, string handling, and state management; it belongs to the Coding & Algorithms domain and tests data-structure and input-event processing competency.
Coding & AlgorithmsOnsite - CloudKitchensMediumSoftware EngineerAnswer static and streaming Top-K queries
This question evaluates understanding of frequency counting, top-K selection, streaming and sliding-window algorithms and data-structure design in the Coding & Algorithms domain, testing both conceptual algorithmic reasoning and practical implementation skills.
Coding & AlgorithmsTechnical Screen - CloudKitchensMediumSoftware EngineerDesign a menu manager with enums
This question evaluates data modeling with enums, efficient data structure selection to meet specified time complexities, API design for CRUD operations, and practical implementation skills including a command-line interface and unit testing.
Coding & AlgorithmsTechnical Screen - CloudKitchensMediumSoftware EngineerDesign an in-memory cloud storage system
This problem tests your ability to design an efficient in-memory storage manager that handles concurrent file operations, user-based quotas, and data eviction policies.
Coding & AlgorithmsTechnical ScreenData StructuresSystem DesignOptimization - CloudKitchensMediumSoftware EngineerDesign receipt system with combo discounts
A CloudKitchens software-engineer technical screen: build a point-of-sale order that prints an itemized receipt on every item tap, then extend it to apply combo discounts. It tests cart data-structure design, receipt formatting, and the algorithm for selecting a valid set of non-overlapping combos.
Coding & AlgorithmsTechnical Screen - CloudKitchensMediumSoftware EngineerImplement concurrent order-accept/pickup simulator
This question evaluates concurrency and synchronization skills, including thread-safe design, inter-thread communication, state tracking, and correctness properties such as race-condition avoidance and deadlock freedom.
Coding & AlgorithmsTechnical Screen - CloudKitchensMediumSoftware EngineerImplement menu parser and serializer
This question evaluates proficiency in text parsing, hierarchical data modeling, tree construction and serialization, string manipulation, and algorithmic complexity (linear time/space).
Coding & AlgorithmsTechnical Screen - CloudflareMediumSoftware EngineerImplement a rule-based rate limiter
Design and implement a multi-rule rate limiter that tracks client request quotas across matching path prefixes using a sliding time window.
Coding & AlgorithmsOnsitesliding-windowdata-structuresdesign - Cockroach LabsMediumSoftware EngineerPoint-in-Time Reads from a Timestamped Key-Value Store
Build a versioned key-value store whose reads return the value a key held at a given timestamp: the latest write at or before that time, or an empty string if there is none. Tests choosing a per-key data layout that keeps point-in-time lookups fast across up to 200,000 operations.
Coding & AlgorithmsOnsite - CodeiumMediumSoftware EngineerFind the third-largest word by length
This question evaluates proficiency in string and array manipulation, ordering by key metrics (string length), and handling tie-breaking via stable ordering, situated in the Coding & Algorithms domain.
Coding & AlgorithmsOnline Assessment - CognitivMediumMachine Learning EngineerMaintain a Streaming Median
This question evaluates understanding of streaming algorithms and dynamic data structures for maintaining order statistics, along with analysis of time complexity and memory trade-offs.
Coding & AlgorithmsTechnical Screen - CohereMediumSoftware EngineerDelete One '5' From a Digit String to Get the Largest Number
Given a digit string containing at least one 5, delete exactly one 5 so the remaining string has the largest possible numeric value, keeping any leading zeros. This intern online-assessment problem tests reasoning about how each digit position affects a number and careful handling of repeated digits.
Coding & AlgorithmsOnsite - CohereMediumMachine Learning EngineerImplement Autoregressive Decoding Strategies
This problem tests your ability to implement common sequence decoding strategies used in large language models by manipulating token probability distributions.
Coding & AlgorithmsOnsiteLLMSamplingSoftmax - CoinbaseMediumSoftware EngineerAnalyze food-delivery data
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Analyze food-delivery data states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerCompute Total Manual Distance
This problem tests your ability to simulate a state-based movement process and calculate cumulative distance based on a non-monotonic set of instructions.
Coding & AlgorithmsOnsiteArraysSimulationMath - CoinbaseMediumSoftware EngineerCount users over n connections
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 users over n connections states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - CoinbaseMediumSoftware EngineerDesign an in-memory database with TTL and backups
This question evaluates skills in designing and implementing in-memory data structures, TTL-based expiration, lexicographic prefix scans, and backup/restore snapshot semantics within the Coding & Algorithms domain.
Coding & AlgorithmsOnline Assessment - CoinbaseMediumSoftware EngineerDesign crypto trading order control API
This question evaluates understanding of state management and finite-state machines, API design for lifecycle control, and implementation of in-memory data structures and transition validation in the Coding & Algorithms category.
Coding & AlgorithmsTechnical Screen - CoinbaseMediumSoftware EngineerDesign order stream with state transitions
Design order stream with state transitions 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 & AlgorithmsOnsite - CoinbaseMediumData ScientistDetect sequence rule and repair anomaly
This question evaluates a candidate's skill in sequence pattern recognition, algorithm design, complexity analysis, and robust integer arithmetic by requiring inference among arithmetic, alternating-difference, geometric, and Fibonacci-plus-constant models while tolerating at most one corrupted term under O(n) time and O(1) extra space constraints.
Coding & AlgorithmsHR Screen - CoinbaseHardSoftware EngineerGenerate NFT metadata and ensure uniqueness
This question evaluates understanding of combinatorics, deterministic pseudo-random generation, and efficient enumeration for producing unique NFT metadata, measuring competency in algorithm design, state-space management, and handling large-scale outputs.
Coding & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerGenerate Weighted Random NFTs with Updates
This question evaluates understanding of weighted random sampling, efficient data structures for maintaining and updating prefix sums, probabilistic reasoning about sampling distributions, and reproducible testing of randomized algorithms within the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerGenerate constrained NFT metadata
Generate constrained NFT metadata 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 & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerImplement Composable Range Iterators
This question evaluates understanding of iterator design, lazy evaluation, composable higher-order combinators (map, filter, zip, take, drop, chain), edge-case handling for forward/backward and negative-step ranges, overflow-safe termination, peekable semantics, iterator invalidation rules, and writing boundary-focused unit tests.
Coding & AlgorithmsOnsite
Citadel
Citi
Cloudflare
Cohere
Coinbase