practice a little every day, paws crossed ♡
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 2491–2520 of 9403 results
- CoinbaseMediumSoftware EngineerImplement banking ops: transfer, top-k, cashback, merge
This question evaluates a candidate's ability to design a robust in-memory banking system, covering transactional correctness, idempotency, concurrency control, delayed cashback scheduling, aggregate top-k queries, and data structure and complexity trade-offs within the Coding & Algorithms domain.
Coding & AlgorithmsOnline Assessment - CoinbaseMediumSoftware EngineerImplement basic pagination for a list
This question evaluates a candidate's competence in array indexing, boundary-condition handling, and simple pagination logic, focusing on correct subarray extraction and off-by-one considerations within given size constraints.
Coding & AlgorithmsTechnical Screen - CoinbaseMediumSoftware EngineerImplement cursor-based query pagination
This question evaluates understanding of cursor-based pagination, deterministic ordering with tie-breakers, cursor encoding, and in-memory data-structure management for efficient filtered queries.
Coding & AlgorithmsTechnical Screen - CoinbaseMediumSoftware EngineerImplement custom iterator classes
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Implement custom iterator classes states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerImplement custom iterators and interfaces
Implement custom iterators and interfaces 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 debounced async autocomplete input
Implement debounced async autocomplete input evaluates requirements, assumptions, structured reasoning, trade-offs, and verification in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Software Engineering FundamentalsTechnical Screen - CoinbaseMediumSoftware EngineerImplement debounced autocomplete component
This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Implement debounced autocomplete component states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Software Engineering FundamentalsTechnical Screen - CoinbaseMediumSoftware EngineerImplement filters and cursor pagination
This question evaluates a candidate's ability to design and implement cursor-based pagination, conjunctive per-field filtering, stable sort key selection, API surface design, and complexity analysis for a database-backed transaction query module.
Data Manipulation (SQL/Python)Onsite - CoinbaseMediumSoftware EngineerImplement iterators and write tests in Java
Implement iterators and write tests in Java 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 - CoinbaseHardMachine Learning EngineerImplement local maxima, bagging, and k-means
This problem tests array traversal for local maxima detection, statistical resampling techniques for bagging, and iterative convergence for k-means clustering.
Coding & AlgorithmsOnline AssessmentAlgorithmsClusteringEnsemble Methods - CoinbaseMediumData ScientistIncrement Digit Array
This question tests the ability to handle array-based arithmetic and carry propagation logic, specifically addressing edge cases like array resizing.
Coding & AlgorithmsOnsiteArraysMathSimulation - CoinbaseEasyProduct ManagerIntroduce Yourself, Why Coinbase, and Career Goals
Prepare strong Coinbase PM interview answers for "tell me about yourself," "why Coinbase," and five-year career goals. Includes answer structure, sample wording, role-fit themes, and pitfalls to avoid.
Behavioral & LeadershipHR Screen - CoinbaseMediumData ScientistInvestigate Anomalies in Coinbase Wallet Engagement Metrics
This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Investigate Anomalies in Coinbase Wallet Engagement Metrics states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - CoinbaseMediumSoftware EngineerMaintain the Kth-Highest User Score with Updates and Removals
This problem tests your ability to maintain a dynamic set of scores and efficiently retrieve the k-th highest element using balanced data structures or ordered collections.
Coding & AlgorithmsOnsiteData StructuresBalanced BSTHash Map - CoinbaseHardSoftware EngineerMaximize block fee with transaction selection
This question evaluates algorithmic optimization and dependency-aware selection skills, focusing on resource-constrained selection (knapsack-like trade-offs) and graph-based dependency reasoning within the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerMaximize profit with transaction fee
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Maximize profit with transaction fee states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsOnsite - CoinbaseMediumSoftware EngineerMaximize profit with transaction fees
This question evaluates algorithm design skills, specifically understanding of dynamic programming and greedy strategies for optimizing profit under transaction fees, along with stateful decision-making and handling cost constraints.
Coding & AlgorithmsOnsite - CoinbaseEasyData ScientistModel Feature Adoption Probability for Users
This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Model Feature Adoption Probability for Users states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathTechnical Screen - CoinbaseMediumData ScientistOptimize no-penalty test strategy
This problem tests your ability to model expected value under time constraints by balancing the probability of success per question against a limited resource pool.
Statistics & MathHR ScreenProbabilityExpected ValueOptimization - CoinbaseMediumSoftware EngineerPaginate forward and backward through results
This question evaluates understanding of pagination mechanics, cursor/token design, array indexing, and state management for bidirectional (forward and backward) navigation.
Coding & AlgorithmsTechnical Screen - CoinbaseMediumSoftware EngineerParse logs and generate NFT attributes
This problem tests your ability to parse structured log strings, group events by metadata, and perform weighted sampling across combinations of attributes.
Coding & AlgorithmsOnsiteParsingHashingProbability - CoinbaseHardSoftware EngineerPick Mempool Transactions for a Block with Parent Dependencies and CPFP
A multi-part coding problem about filling a block of capacity 100 from a large, unsorted mempool of transactions with fees and sizes, where speed matters more than optimality. Later parts add parent transactions that must be included first, child-pays-for-parent across multi-level chains, and an optional minimum fee for a new child.
Software Engineering FundamentalsTechnical Screen - CoinbaseHardFrontend EngineerPresent a Previous Project Deep Dive
This question evaluates technical depth, architectural reasoning, leadership, and cross-team collaboration skills within frontend engineering, focusing on system/frontend architecture, tradeoff analysis, incident management, and measurable impact.
Behavioral & LeadershipOnsite - CoinbaseMediumSoftware EngineerResolve a Disagreement in Code Review
This question tests your ability to navigate technical conflict, exercise professional judgment, and demonstrate collaborative communication skills during a pull request review.
Behavioral & LeadershipOnsiteCommunicationCode ReviewConflict Resolution - CoinbaseMediumSoftware EngineerSchedule Fixed-Order Tasks with a Cooldown
Calculate the total days required to run a sequence of tasks in a strict, fixed order where identical tasks must be separated by a specified cooldown period.
Coding & AlgorithmsOnsiteArrayHash TableGreedy - CoinbaseMediumSoftware EngineerSelect transactions to maximize fees under size
This problem tests your ability to solve a variation of the 0/1 Knapsack problem where items have both a cost (size) and a value (fee).
Coding & AlgorithmsOnsiteDynamic ProgrammingOptimizationAlgorithms - CoinbaseMediumData ScientistSolve Aptitude Test: Logical, Numerical, Verbal Reasoning
This question evaluates logical, numerical, and verbal reasoning along with rapid pattern recognition and time-limited decision-making relevant to pre-employment aptitude screens for data science roles.
Coding & AlgorithmsOnline Assessment - CoinbaseHardData ScientistSolve the 12-coin balance puzzle
This question evaluates understanding of combinatorial reasoning, information theory, and decision-tree construction for identifying a single counterfeit coin and whether it is heavier or lighter using constrained balance-scale observations.
Statistics & MathTechnical Screen - CoinbaseMediumData ScientistWrite SQL and Python for funnels/retention
This question evaluates SQL and Python data-manipulation skills, including event-to-session joins, temporal window filtering, deduplication, JSON metadata handling, and computation of funnel and retention metrics like daily unique users and conversion rates.
Data Manipulation (SQL/Python)HR Screen - CoinbaseMediumMachine Learning EngineerWrite SQL to rank top products per category
This question evaluates SQL proficiency in aggregation, time-based filtering, joining transactional and reference tables, and ranking/windowing techniques to compute and deterministically order product revenue with tie-breaking by product_id.
Coding & AlgorithmsOnsite
Coinbase