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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 661–690 of 781 results
- StateMediumSoftware EngineerExplain Java Automatic Memory Management: Heap, Reachability and Garbage Collectors
Describe how Java manages memory automatically, from object allocation on the heap to how the JVM decides which objects are unreachable and reclaims them. The question tests knowledge of garbage collection algorithms, generational collection, collector trade-offs and how memory leaks still happen in Java programs.
Software Engineering FundamentalsOnline Assessment - StripeMediumSoftware EngineerBuild searchable list and highlight max transaction
This question evaluates competency in frontend UI development, state management, real-time filtering, and aggregate computation (finding and highlighting maximum values) with attention to algorithmic efficiency; domain: frontend UI engineering (Other/Miscellaneous).
Software Engineering FundamentalsOnline Assessment - StripeHardSoftware EngineerCalculate Per-User Usage Charges
This problem tests your ability to efficiently process and aggregate time-series usage data while handling complex proration rules and tiered pricing models.
Coding & AlgorithmsOnline AssessmentArraysSortingMath - StripeHardSoftware EngineerDesign a Fixed-Position Payment Command State Machine
Design a fixed-position payment-command parser and state machine while preserving empty fields and clarifying approval, capture, cancellation, and retry semantics.
Software Engineering FundamentalsOnline Assessment - StripeHardData ScientistDesign a model for subscription adoption prediction
This question evaluates a candidate's ability to design and productionize a supervised machine-learning pipeline for predicting subscription adoption, testing competencies in labeling strategy, leakage identification and prevention, feature engineering from transactional and merchant metadata, model selection and calibration, evaluation with time-based validation, and post-deployment monitoring. It is commonly asked in the Machine Learning domain for Data Scientist roles because it assesses practical application and production-ready design along with conceptual understanding of time-based splits, class imbalance, performance metrics, and drift detection.
Machine LearningOnline Assessment - StripeHardSoftware EngineerFind Live Hand-Off Windows Between Follow-the-Sun Support Teams
Find recurring weekly windows where at least two regional support teams are simultaneously online, after converting each team's local shift schedule to a shared UTC timeline and handling the week's wraparound, then filter by a lead time, a minimum overlap length and a results cap. Tests interval sweeping, time-zone arithmetic and turning a loosely specified brief into exact rules.
Software Engineering FundamentalsOnline Assessmentintervalssweep-linetime-zones - StripeHardSoftware EngineerFind Weekly Deployment Windows Across Time Zones
Determine the first k non-overlapping deployment windows across a 3-week search horizon by mapping weekly recurring local allow and freeze rules into a repeating UTC timeline.
Coding & AlgorithmsOnline AssessmentIntervalsPrefix SumSliding Window - StripeMediumSoftware EngineerImplement a Datacenter Request Router
This problem tests the ability to manage stateful datacenter metadata and implement a routing algorithm that prioritizes proximity (Haversine distance) while respecting capacity constraints.
Coding & AlgorithmsOnline AssessmentGeometryHash MapSorting - StripeMediumSoftware EngineerImplement bitmap font render/compress/invert
This problem tests your ability to manipulate 2D bit arrays, implement Run-Length Encoding (RLE) for data compression, and perform grid-based coordinate transformations.
Coding & AlgorithmsOnline AssessmentArraysStringsCompression - StripeMediumSoftware EngineerImplement multi-network card validator with Luhn
This question evaluates a candidate's ability to implement and reason about the Luhn checksum, multi-network payment card format validation, combinatorial completion for redacted digits, single-error correction models, and efficient search/pruning with deterministic duplicate avoidance.
Coding & AlgorithmsOnline Assessment - StripeEasySoftware EngineerImplement stateful connection router simulator
This question evaluates design and implementation skills for a stateful connection router, focusing on round-robin load distribution, connection lifecycle handling (duplicate connects, disconnects, shutdowns), and per-target capacity and mapping management.
Coding & AlgorithmsOnline Assessment - StripeMediumData ScientistPrioritize a 6-hour take-home effectively
This question evaluates a candidate's ability to scope and time-box work, prioritize analyses and features, articulate trade-offs and risks, and produce concise deliverables under a tight deadline, reflecting judgment and leadership competencies for a Data Scientist.
Behavioral & LeadershipOnline Assessment - StripeMediumSoftware EngineerRegister Data Centers and Route to the Nearest Healthy Region
Implement a stateful command processor to register data centers, update their operational health, and route incoming requests to the nearest healthy data center using the Haversine distance formula.
Coding & AlgorithmsOnline AssessmentDesignGeometryParsing - StripeEasySoftware EngineerSpecify Proximity-Based Request Routing
Clarify proximity metrics, destination eligibility, tie rules, and capacity before designing a request-routing algorithm.
Software Engineering FundamentalsOnline Assessment - StripeHardSoftware EngineerSubtract Blocked Periods from Allowed Deployment Windows
Compute available deployment windows by merging allowed and blocked half-open intervals, subtracting overlaps, and returning maximal sorted nonempty ranges.
Coding & AlgorithmsOnline Assessment - StripeMediumData ScientistWrite SQL to detect recurring non-subscription users
This question evaluates a candidate's ability to perform advanced SQL data manipulation and temporal pattern detection in transactional datasets, including attribute-based matching (amount and card fingerprint) and filtering by transaction status.
Data Manipulation (SQL/Python)Online Assessment - TargetMediumBackend EngineerFind the Closest Candidate String by Edit Distance
This problem tests the implementation of the Levenshtein distance algorithm (Edit Distance) and the ability to manage tie-breaking logic when comparing multiple strings against a query.
Coding & AlgorithmsOnline AssessmentDynamic ProgrammingStringsOptimization - TargetMediumBackend EngineerImplement a Synchronized First-Available Seat Allocator
This problem tests your ability to design a thread-safe allocator that manages a finite resource pool under high concurrency, focusing on atomic updates and race condition prevention.
Software Engineering FundamentalsOnline AssessmentConcurrencyAtomic OperationsThread Safety - TeslaEasySoftware EngineerGenerate Per-Position Guess Feedback
This problem tests your ability to process strings and manage state (character frequency) to determine exact matches versus partial matches, commonly used in word-guessing games.
Coding & AlgorithmsOnline AssessmentStringHash MapArray - TestGorillaMediumSoftware EngineerAssess Spring IoC, AOP, JDBC, Security
Assess Spring IoC, AOP, JDBC, Security evaluates engineering fundamentals, trade-offs, examples, pitfalls, and operational implications 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 FundamentalsOnline Assessment - The Trade DeskMediumSoftware EngineerDesign a Recipe Manager
Evaluates API and in-memory data structure design, search and sorting semantics, user-associated operations, versioning/audit history, data normalization, and edge-case handling within the Software Engineering Fundamentals domain.
Software Engineering FundamentalsOnline Assessment - The Trade DeskMediumSoftware EngineerImplement a Cloud Storage Service
This question evaluates a candidate's ability to implement an in-memory cloud storage system, exercising skills in data structures and stateful API design, string handling and pattern matching, sorting and eviction algorithms, and per-user resource accounting.
Coding & AlgorithmsOnline Assessment - Thomson ReutersEasyMachine Learning EngineerApplied Machine Learning Assessment: Metrics, Evaluation, and NLP Fundamentals
Practice a Thomson Reuters machine learning interview question about applied machine learning assessment: metrics, evaluation, and nlp fundamentals. The prompt covers objective framing, data assumptions, evaluation, trade-offs, and production risks without giving away the answer.
Machine LearningOnline Assessment - TikTokHardMachine Learning EngineerAnswer ML fundamentals and diagnostics questions
This problem tests your theoretical understanding of model diagnostics, ensemble learning mechanics, and the trade-offs between optimization strategies in machine learning.
Machine LearningOnline AssessmentEnsemble MethodsRegularizationMetrics - TikTokMediumProduct ManagerBreak a Palindrome Algorithm
Practice the greedy algorithm for breaking a palindrome into the lexicographically smallest non-palindrome by one character replacement. The solution explains scanning the left half, skipping the middle character, changing the first non-a to a, handling all-a cases, proving correctness, and analyzing complexity.
Product / Decision MakingOnline Assessment - TikTokMediumData ScientistCount buggy vs non-buggy by employer
This question evaluates proficiency in SQL data manipulation—particularly conditional aggregation and join semantics—for counting categorized records across related tables in a data science context.
Data Manipulation (SQL/Python)Online Assessment - TikTokMediumSoftware EngineerImplement list, form, and API rendering with pitfalls
This question evaluates front-end web development competencies including local-state list rendering, form submission and validation behavior, client API integration with loading/success/error states, accessibility practices, idempotent update handling, and predictable re-rendering.
Software Engineering FundamentalsOnline Assessment - TikTokHardMachine Learning EngineerImplement local maxima, bagging, and k-means
This problem tests your ability to implement a sliding window peak detector, a bootstrapping ensemble sampler, and a centroid-based clustering algorithm from scratch.
Coding & AlgorithmsOnline AssessmentAlgorithmsClusteringEnsemble Learning - TikTokMediumData ScientistMaximize Distinct Purchases Within Budget Constraints
This question evaluates understanding of selection and optimization under budget constraints, algorithmic efficiency, and the ability to implement correct logic for maximizing the number of distinct items purchased.
Coding & AlgorithmsOnline Assessment - TikTokMediumData ScientistMaximize products bought under budget
This question evaluates algorithmic problem-solving skills including sorting, prefix-sum accumulation, binary search, greedy selection, careful tie-breaking for lexicographic order, and complexity analysis.
Coding & AlgorithmsOnline Assessment
Stripe
Tesla
The Trade Desk
TikTok