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 1411–1440 of 1706 results
- StackAdaptEasySoftware EngineerDesign a time-windowed key-value store
This question evaluates a candidate's ability to design efficient data structures and algorithms for a time-windowed key-value store, focusing on expiration handling, update semantics, and maintaining aggregate metrics under memory constraints.
Coding & AlgorithmsTechnical Screen - StackAdaptEasyMachine Learning EngineerMaintain the Median of an Integer Stream
This problem tests your ability to maintain dynamic statistics in a data stream using efficient heap-based data structures.
Coding & AlgorithmsTechnical ScreenHeapsData StreamsAlgorithms - StravaMediumSoftware EngineerFirst Climb in Elevation Samples, Strict and With a Tolerated Partial Descent
Given elevation samples taken at regular intervals, return the start and end indices of the first climb, first under strict rules where elevation may never drop and then allowing a temporary descent limited to a fraction of the gain so far. Tests precise index semantics, lookahead and careful state tracking.
Coding & AlgorithmsTechnical Screen - StripeMediumSoftware EngineerAssign tasks to workers with types and accounts
This problem tests the ability to manage task scheduling with specific affinity constraints and varying worker processing times using an efficient priority-based simulation.
Coding & AlgorithmsTechnical ScreenAlgorithmsSchedulingPriority Queue - StripeMediumSoftware EngineerCalculate transaction fees from CSV records
Implement a fee calculation engine that parses CSV transaction records, applies multi-attribute pricing rules and merchant volume discounts, and accurately rounds fee amounts in cents.
Coding & AlgorithmsTechnical ScreenDesign PatternString ParsingState Tracking - StripeMediumData EngineerCompute shipping cost with tiered pricing
Evaluates implementation-level algorithmic logic for tiered pricing, covering per-unit aggregation, interval reasoning, and mixed incremental vs fixed pricing models within the Coding & Algorithms domain and Data Engineering role; abstraction level is practical, implementation-focused business logic and data transformation.
Coding & AlgorithmsTechnical Screen - StripeMediumSoftware EngineerDesign a subscription email scheduler with changes and renewals
This question evaluates event-driven scheduling, deterministic time-based ordering, stateful account updates for plan changes and renewals, and algorithmic merging of notification streams in the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - StripeMediumSoftware EngineerEvaluate Ordered Access-Control Rules
Implement an access-control evaluator that parses rule strings with conditions and returns the first matching decision (ACCEPT or BLOCK).
Coding & AlgorithmsTechnical ScreenStringsParsingDesign - StripeMediumSoftware EngineerFind linked merchants by shared fields
This question tests the ability to model entity relationships using a graph representation and implement a traversal algorithm to identify connected components based on shared identity fields.
Coding & AlgorithmsTechnical ScreenGraphsHash MapsDisjoint Set Union - StripeMediumSoftware EngineerFind linked user records by similarity
This question evaluates the ability to compute weighted field-based similarity and reason about adjacency relationships in an undirected graph, testing competencies in similarity scoring, record linkage, and basic graph traversal.
Coding & AlgorithmsTechnical Screen - StripeMediumSoftware EngineerFind linked user records by weighted similarity
This problem tests your ability to model relationships as a graph and compute connected components based on weighted similarity scores between user records.
Coding & AlgorithmsTechnical ScreenGraphDSUOptimization - StripeHardSoftware EngineerGenerate Available 30-Minute Time Slots
This problem tests your ability to manipulate time intervals, handle recurring weekly schedules, and perform intersection logic between availability windows and existing booked appointments.
Coding & AlgorithmsTechnical ScreenIntervalsDatetimeScheduling - StripeMediumSoftware EngineerHow to find the cheapest flight within K stops
This problem tests your ability to find the shortest path in a weighted graph under a specific constraint on the number of edges (stops).
Coding & AlgorithmsTechnical ScreenGraphDynamic ProgrammingShortest Path - StripeMediumSoftware EngineerHow to settle multi-person debts in minimum transactions
Tests algorithm design and combinatorial search to settle multi-party debts with the minimum number of transfer transactions.
Coding & AlgorithmsTechnical ScreenBacktrackingDynamic ProgrammingBitmask - StripeMediumSoftware EngineerImplement JSON parsing and HTTP integration tasks
Tests practical software engineering skills in parsing JSON data, constructing batch HTTP requests, mapping returned attributes (such as color codes to coordinate points), and handling API errors.
Coding & AlgorithmsTechnical ScreenAPI DesignJSONHTTP Client - StripeMediumSoftware EngineerImplement multi-part cost calculator
This question evaluates a candidate's ability to implement robust data-processing and numeric computation logic for a multi-part cost calculator, covering input validation, per-item discounts and tax, sorting semantics, multi-currency conversion, and precise monetary rounding.
Coding & AlgorithmsTechnical Screen - StripeMediumData ScientistImplement streaming per-user reservoir sampling
This question evaluates a candidate's competency in streaming algorithms, per-user reservoir sampling, probabilistic reasoning and proof of correctness, concurrent/distributed merging, and engineering trade-offs for memory and amortized update efficiency.
Coding & AlgorithmsTechnical Screen - StripeEasyData ScientistMatch payments to invoices by memo or amount
This question evaluates string parsing, record linkage, and algorithmic matching skills for data reconciliation tasks, including handling messy memo text, exact amount matches, and tie-breaking by earliest due date.
Coding & AlgorithmsTechnical Screen - StripeMediumSoftware EngineerMatch payments to invoices with fallback rules
This problem tests the ability to implement a multi-pass matching algorithm that prioritizes exact identifier matches before applying fuzzy numeric heuristics.
Coding & AlgorithmsTechnical ScreenHashMapsAlgorithmsData Structures - StripeMediumSoftware EngineerMinimize total factory cost with distance penalties
This problem tests your ability to use dynamic programming to minimize a total cost function that incorporates both intrinsic production costs and location-based transition penalties.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingOptimizationAlgorithms - StripeMediumSoftware EngineerParse and Format Arbitrarily Nested Tasks from CSV
Tests parsing RFC 4180-compliant CSV records containing hierarchical tasks and rendering an arbitrarily nested forest with proper tree line prefixes (`├── `, `└── `, and `│ `).
Coding & AlgorithmsTechnical Screentreerecursionstring-parsing - StripeMediumSoftware EngineerPlan bicycle routes on a city map
This question evaluates graph algorithms and pathfinding competencies, multi-criteria optimization and weighting, data structure selection, heuristic design, handling dynamic updates and closures, and correctness and edge-case reasoning for route planning.
Coding & AlgorithmsTechnical Screen - StripeMediumSoftware EngineerProcess Transactions and Compute Balances
This problem tests your ability to manage stateful account data, handle time-ordered transaction processing, and implement basic validation logic for financial integrity.
Coding & AlgorithmsTechnical ScreenSortingHash MapSimulation - StripeMediumSoftware EngineerProcess auth requests with fraud rules
This question evaluates a candidate's ability to implement stateful stream processing and event handling, including applying time-scoped fraud rules to authorization requests, maintaining chronological ordering, and producing verified outputs via unit tests.
Coding & AlgorithmsTechnical Screen - StripeMediumSoftware EngineerPropagate runtime ID across API requests
Implement a request interpolator that traverses nested request payloads and URLs to replace placeholder variables with runtime IDs while preserving native data types.
Coding & AlgorithmsTechnical ScreenRecursionString ParsingJSON - StripeMediumSoftware EngineerResolve user roles across account hierarchy
This problem tests your ability to navigate hierarchical structures (a tree of accounts) and perform efficient permission aggregation using set operations.
Coding & AlgorithmsTechnical ScreenGraphHash MapHierarchy - StripeHardSoftware EngineerSplit-Tender Payment Events with Gift Card Expiry, ZIP Surcharges and Refunds
Implement a payment event processor for split-tender retail purchases, where each charge spends a customer's gift cards before billing the rest to a credit card. It tests precise simulation: earliest-expiry card priority with lexicographic tie-breaks, ZIP-range surcharges on the credit card portion, refunds split between card and store credit, and exact output formatting.
Coding & AlgorithmsTechnical Screen - StripeHardSoftware EngineerTheme-Park Wristband Payments: Expiring Credits, Zone Fees, Refunds
Process a chronological log of theme-park wristband events that spend expiring ride credits before a linked card, apply per-zone card surcharges, and split refunds between the card and new store credit.
Coding & AlgorithmsTechnical Screensimulationevent-processinggreedy - StripeHardSoftware EngineerTransit Wallet Ledger: Expiring Vouchers, Zone Fees and Refunds
Process a stream of wallet events where purchases spend expiring vouchers in priority order before charging a card with zone-based fees, and refunds split between card and new store credit. Tests careful rule-by-rule simulation and integer money math.
Coding & AlgorithmsTechnical Screensimulationparsingsorting - StripeMediumSoftware EngineerValidate KYC CSV Records
Implement a KYC CSV record validator that parses customer records, normalizes fields, and validates tax IDs and owner name matches.
Coding & AlgorithmsTechnical ScreenStringsData ParsingRule Validation
StackAdapt
Stripe