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 1681–1710 of 3640 results
- J.P. MorganMediumSoftware Engineer IIExplain Why You Are Changing Jobs and How You Communicated the Decision
This question assesses the candidate's ability to articulate professional motivations for moving roles while maintaining a positive narrative about their current employer and handling transitions with professional integrity.
Behavioral & LeadershipOnsiteCommunicationCareer GrowthProfessionalism - J.P. MorganMediumSoftware Engineer IIExplain a Project Architecture End to End
Tests your ability to present a production system architecture end-to-end, detailing data flow, ownership boundaries, database indexing and partitioning strategies, resilience patterns, and concrete architectural trade-offs.
System DesignOnsiteDatabase OptimizationArchitectureData Modeling - J.P. MorganMediumSoftware Engineer IIFind the Maximum-Sum Contiguous Subarray
Implement Kadane's algorithm to find the maximum sum of a non-empty contiguous subarray in linear time and constant auxiliary space, with proper handling for all-negative inputs and potential 64-bit integer overflow.
Coding & AlgorithmsOnsitedynamic-programmingarrayskadanes-algorithm - J.P. MorganEasySoftware EngineerGroup strings that are anagrams
This problem tests your ability to efficiently group strings based on their character counts and your knowledge of hash maps to solve anagram-related categorization problems.
Coding & AlgorithmsOnsiteHash MapString ManipulationAlgorithms - J.P. MorganMediumSoftware Engineer IIImplement Merge Sort
This problem tests your ability to implement the Divide and Conquer paradigm, specifically the recursive merge sort algorithm, while maintaining stability and managing auxiliary space.
Coding & AlgorithmsOnsiteSortingDivide and ConquerRecursion - J.P. MorganMediumSoftware EngineerJava Core Deep Dive: Concurrent Collections and Java 8 Features
This question tests your understanding of thread-safety in Java collections and your ability to refactor imperative code into functional Java 8 style streams.
Software Engineering FundamentalsOnsiteJavaConcurrencyCollections - J.P. MorganMediumSoftware Engineer IIOptimize User-and-Region Queries on a Million-Row Table
Evaluate and design database access patterns, indexing strategies, and scaling techniques (partitioning, sharding, replication) for a financial user-profile system with high regional skew and frequent lookups.
System DesignOnsiteDatabase OptimizationIndexingPartitioning - J.P. MorganMediumSoftware Engineer IIReason About Concurrency, CAP Trade-Offs, and Kubernetes Scaling
This problem tests your understanding of fundamental concurrency concepts, distributed systems trade-offs under partition, and the practical application of Kubernetes scaling mechanisms in a high-throughput environment.
Software Engineering FundamentalsOnsiteConcurrencyCAP TheoremKubernetes - J.P. MorganMediumSoftware Engineer IIReturn the K Largest Integers
This problem tests the ability to efficiently find the k largest elements in an unsorted array using heap-based data structures to optimize for cases where k is significantly smaller than the input size.
Coding & AlgorithmsOnsiteHeapSortingAlgorithms - J.P. MorganMediumData ScientistSolve tiling, probability, and nested-radical puzzles
This problem tests your ability to derive recurrence relations for combinatorial tiling, solve infinite series limits, and calculate exact probabilities using combinations.
Coding & AlgorithmsOnsiteCombinatoricsDynamic ProgrammingProbability - J.P. MorganMediumData ScientistTest whether samples follow a binomial distribution
This problem tests the application of goodness-of-fit testing to verify if a set of discrete observations conforms to a binomial distribution.
Machine LearningOnsiteStatisticsHypothesis TestingProbability - J.P. MorganMediumSoftware EngineerTwo Sum — Indices Summing to a Target
This question tests the ability to trade space for time by using a hash map to achieve linear time complexity when finding a pair of elements that satisfy a target sum.
Coding & AlgorithmsOnsiteArraysHash MapsAlgorithms - Jane StreetEasySoftware EngineerDesign exchange–trading system message flow
This question evaluates a candidate's knowledge of distributed messaging protocols, fault-tolerant system design, and financial trading interface competencies, including defining message contracts, session management, and guarantees like idempotency and ordering.
System DesignOnsite - Jane StreetMediumQuantitative TraderDice Duel: 30-Sided Die vs. 20-Sided Die with One Blind Reroll
This question evaluates probabilistic reasoning, expected-value comparison, and decision-making under uncertainty in discrete random processes. It is commonly asked to test a candidate's ability to reason about optimal stochastic decisions and trade-offs in blind reroll scenarios, classified under probability and decision theory within the Machine Learning domain and assessing conceptual understanding rather than practical implementation.
Machine LearningOnsite - Jane StreetMediumQuantitative ResearcherFive Pumpkins Weighed in Every Pair: Find the Total Weight
This question evaluates combinatorial counting, algebraic reasoning, and mental-arithmetic skills by testing understanding of pairwise sums and how individual elements contribute to aggregate totals.
Software Engineering FundamentalsOnsite - Jane StreetMediumQuantitative ResearcherMinimum Common Pairwise Correlation Among Seven Identically Distributed Random Variables
This question evaluates understanding of correlation constraints, covariance/correlation matrix structure, and spectral analysis, combining probability, statistics, and linear algebra competencies within the Machine Learning/Data Science domain.
Machine LearningOnsite - Jane StreetMediumQuantitative TraderOptimal Stopping for Die Rolls That Bust on Perfect Squares
This question evaluates probabilistic reasoning and optimal stopping competency, testing understanding of Markov decision processes, expected-value calculations, and risk trade-offs in stochastic processes.
Coding & AlgorithmsOnsite - Jane StreetHardSoftware EngineerOptimize trade PnL table updates
Design an incremental PnL tracking engine that efficiently aggregates realized and unrealized profit-and-loss across overlapping predicate views under high-frequency trade and price tick updates.
Coding & AlgorithmsOnsiteDesignData StructuresCaching - Jane StreetEasySoftware EngineerSort trade executions into a canonical order
This question evaluates a candidate's ability to enforce deterministic ordering and data normalization of time-series trade execution records, testing competencies in multi-key sorting, tie-breaking logic, and performance with large inputs.
Coding & AlgorithmsOnsite - Jane StreetMediumQuantitative TraderTwo Opaque Boxes: Place or Take for Maximum Expected Payoff
This question evaluates probabilistic reasoning, expected-value analysis, and sequential decision-making under uncertainty, testing competency in stochastic modeling, combinatorics, and optimization.
Coding & AlgorithmsOnsite - Jane StreetEasySoftware EngineerValidate order book data across multiple databases
This question evaluates a candidate's competency in designing data-validation and reconciliation systems for financial order books, including defining invariants, ensuring cross-database consistency, and handling edge cases like partial fills, cancels, out-of-order events, duplicates, and replayed messages.
System DesignOnsite - Jane StreetMediumQuantitative ResearcherWhich Dice Game Wins More Often: One Six in 4 Rolls, or Double Sixes in 24 Rolls?
This question evaluates probabilistic reasoning and statistical intuition, focusing on independence of trials, event probability versus expected value, and the ability to compare probabilities of rare events.
Software Engineering FundamentalsOnsite - Jump TradingMediumQuantitative ResearcherMaintain a Fixed-Window Rolling Mean in Constant Time
Implement an efficient sliding-window mean calculation over a stream or sequence of signed integers. Tests sliding window mechanics, constant-time updates, handling integer overflow, and edge cases.
Coding & AlgorithmsOnsiteSliding WindowArraysStreaming - KikoffMediumSoftware EngineerDesign a Credit Scoring Platform
This question assesses the ability to design an end-to-end machine learning system for real-time credit risk assessment, focusing on data pipelines, model inference, and regulatory compliance.
ML System DesignOnsiteScalabilityFeature StoreCompliance - LangchainMediumSoftware EngineerOptimize Object-Backed APIs and Design an LLM Observability Platform
Design a high-throughput LLM observability and tracing platform that reliably captures spans, aggregates token billing, and provides low-latency trace retrieval over an object-storage backend.
System DesignOnsiteObservabilityObject StorageStreaming - LatitudeaiMediumBackend EngineerDesign a Thread-Safe Bounded Blocking Queue
Tests your ability to design a concurrent, thread-safe bounded blocking queue using synchronization primitives, handle edge cases like spurious wakeups and timeouts, and cleanly coordinate shutdown across multiple threads.
Software Engineering FundamentalsOnsiteConcurrencyMultithreadingQueue - Lead BankMediumSoftware EngineerDesign Room-Level Hotel Reservations Without Double Booking
This problem tests the ability to design a distributed reservation system that ensures strong consistency for inventory management while handling high-concurrency read operations.
System DesignOnsiteConcurrencyDatabaseDistributed Systems - Lead BankMediumSoftware EngineerDesign a hotel reservation system
This problem tests your ability to design a distributed reservation system that handles high concurrency, prevents double-booking, and maintains eventual consistency with external payment services.
System DesignOnsiteConcurrencyDistributed SystemsDatabase Modeling - Lead BankMediumSoftware EngineerExplain PM collaboration and AI code quality
This question assesses the candidate's ability to balance rapid product delivery with long-term code maintainability, specifically when integrating AI-generated code or working under aggressive PM timelines.
Behavioral & LeadershipOnsiteBehavioralLeadershipAI-Assisted Development - Lead BankMediumSoftware EngineerProcess Calendar Events with Deletion, Pagination, and Overlap Queries
This problem tests your ability to manage a dynamic set of time-interval events using a data structure that allows for logarithmic insertions, deletions, and efficient range-based queries.
Coding & AlgorithmsOnsiteData StructuresIntervalsPagination
J.P. Morgan
Jane Street