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Software Engineer 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.
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Showing 1861–1890 of 2629 results
- PeregrineMediumSoftware EngineerFetch, group, and print paginated activities
This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Fetch, group, and print paginated activities states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - PermitflowMediumSoftware EngineerDistinguish Permit Requirement Outcomes
This problem tests your ability to model state transitions based on complex rule sets and implement efficient logic to resolve status precedence when multiple criteria are met.
Coding & AlgorithmsTechnical ScreenAlgorithmsLogicSet Theory - PerplexityMediumSoftware EngineerDesign a CreditTracker with expirations
This question evaluates a candidate's ability to design and implement data structures and algorithms for managing time-bound resources with non-monotonic (out-of-order) operations, emphasizing correctness and efficiency within the coding & algorithms domain.
Coding & AlgorithmsTechnical Screen - PerplexityMediumSoftware EngineerImplement Dependency-Aware To-Do List
Design an in-memory task management system that tracks directed dependencies between tasks, prevents cycles, and unblocks dependent tasks upon completion.
Coding & AlgorithmsTechnical ScreenGraphDesignTopological Sort - PerplexityHardSoftware EngineerImplement Task Dependencies and Failure
This question evaluates understanding of graph-based data structures and algorithms for modeling bidirectional task dependencies, status tracking, and efficient cascading failure propagation in an in-memory task manager.
Coding & AlgorithmsTechnical Screen - PerplexityMediumSoftware EngineerImplement time-versioned KV store with restore
This question evaluates a candidate's ability to design and implement a time-versioned key–value store, assessing knowledge of temporal data structures, versioning semantics, time-travel and range queries, deletion semantics, and rollback/restoration.
Coding & AlgorithmsOnline Assessment - PersonaHardSoftware EngineerImplement a Versioned Key-Value File Store
Practice a Persona coding interview problem focused on implement a versioned key-value file store. The prompt emphasizes edge cases, clean implementation, and verifiable test behavior without revealing the solution.
Coding & AlgorithmsOnline Assessment - PikaHardSoftware EngineerEvaluate Spreadsheet Cells and Reject Circular References
Implement a small spreadsheet whose cells hold integers or single-reference formulas with offsets. Evaluate through current dependencies, propagate updates, report unset chains, and reject a formula atomically whenever it would introduce a circular reference.
Coding & AlgorithmsTechnical Screen - PikaMediumSoftware EngineerImplement text formatter and sum subarray products
This question evaluates algorithmic problem-solving and implementation skills across string formatting (line breaking and space management) and array-based combinatorial computation (sum of subarray products), emphasizing correctness, edge-case handling, and analysis of time and space complexity.
Coding & AlgorithmsOnline Assessment - PilotEasySoftware EngineerSolve Anagram Without Sorting
This question evaluates proficiency in string manipulation, character frequency analysis, and asymptotic time/space complexity reasoning. It is commonly asked in the coding & algorithms domain to test practical application of basic data structures (string processing and frequency-based counting), correctness under input constraints, and the ability to design efficient, linear-time solutions rather than purely conceptual reasoning.
Coding & AlgorithmsTechnical Screen - PinduoduoMediumSoftware EngineerClockwise Spiral Matrix Traversal That Turns at Blocked Cells
Return the values of a matrix in clockwise spiral order starting from the top-left cell, then extend the walk so that blocked cells force clockwise turns and can end it early. Tests precise grid simulation, direction rotation, visited and boundary checks, and an unambiguous stopping rule.
Coding & AlgorithmsTechnical Screen - PinduoduoMediumSoftware EngineerCompute longest increasing subsequence length
This question tests the ability to solve the Longest Increasing Subsequence (LIS) problem, specifically targeting the transition from a standard dynamic programming approach to an optimized binary search solution.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingBinary SearchArrays - PinduoduoHardSoftware EngineerCount Longest Substrings After Character Replacements
This problem tests the sliding window technique with dynamic constraints, requiring an efficient way to track window state and calculate valid substring counts.
Coding & AlgorithmsTechnical ScreenSliding WindowTwo PointersStrings - PinduoduoMediumSoftware EngineerDesign a Recency-Eviction Cache
This problem tests your ability to implement a Least Recently Used (LRU) cache using a combination of a hash map and a doubly linked list to achieve constant time operations.
Coding & AlgorithmsTechnical ScreenHash MapLinked ListLRU Cache - PinduoduoHardSoftware EngineerFind Shortest Square-Sum Path
This problem tests your ability to model a shortest-path graph search problem where states are integers and transitions involve adding perfect squares.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingBFSNumber Theory - PinduoduoMediumSoftware EngineerGenerate a Matrix in Spiral Order
This problem tests your ability to simulate a specific traversal pattern in a 2D grid and maintain precise boundary pointers to fill the matrix correctly.
Coding & AlgorithmsTechnical ScreenArrayMatrixSimulation - PinduoduoEasySoftware EngineerGenerate a Spiral Matrix
This problem tests your ability to manage matrix traversal coordinates and maintain state (direction and boundaries) while iteratively filling a grid.
Coding & AlgorithmsTechnical ScreenArraysMatricesSimulation - PinduoduoMediumSoftware EngineerLongest Single-Letter Substring After at Most k Character Changes
Given a string of uppercase letters and a budget of at most k single-character changes, find the longest run of one repeated letter that can be produced. Tests reasoning about which substrings can be made uniform, efficient counting, and a near-linear solution for strings of up to 100,000 characters.
Coding & AlgorithmsTechnical Screen - PinduoduoMediumSoftware EngineerTraverse a Matrix in Spiral Order
Traverse a rectangular matrix in clockwise spiral order using shrinking boundaries. Handle empty, single-row, and single-column inputs without duplicates while achieving linear time and constant auxiliary space beyond the result.
Coding & AlgorithmsTechnical Screen - PinterestMediumSoftware EngineerAnswer Policy Violation Log Queries
Design an in-memory query engine over a timestamp-sorted policy violation log to support aggregate, point, and range queries efficiently using hash maps and binary search.
Coding & AlgorithmsTechnical Screenhash-tablebinary-searchdesign - PinterestMediumSoftware EngineerAssign Pins to Shortest Columns
This question evaluates understanding of greedy assignment strategies and data structures for maintaining and updating minimums in an online allocation problem, while also testing load-balancing reasoning and analysis of time and space complexity.
Coding & AlgorithmsTechnical Screen - PinterestMediumSoftware EngineerCollect Pins from Reachable Boards
Implement a breadth-first graph traversal over a collection of boards to collect unique pins in discovery order, handling cycles, shared children, and invalid references.
Coding & AlgorithmsOnline AssessmentGraphBFSHash Table - PinterestMediumSoftware EngineerCompute reachable cells for a cleaning robot
This problem tests graph traversal techniques (BFS/DFS) on a 2D grid, focusing on efficient coordinate management and state representation when navigating obstacles.
Coding & AlgorithmsOnsiteBFSGraph Traversal2D Grid - PinterestHardSoftware EngineerCount Distinct Active Pins per Time Segment from Overlapping Interaction Logs
Process overlapping pin interaction logs to calculate the number of distinct active pins over continuous time segments. Tests interval merging, line sweep techniques, and boundary handling.
Coding & AlgorithmsOnsitesweep-lineintervalssorting - PinterestMediumSoftware EngineerCross-reference logs to flag spam numbers
This question evaluates proficiency with data structures (such as hash maps), parsing and deduplication, frequency counting, input validation, and analysis of time and space complexity.
Coding & AlgorithmsOnsite - PinterestMediumSoftware EngineerDecide target via subsequence plus/multiply expression
A Pinterest software-engineer coding screen: given positive 32-bit integers and a target, decide whether some subsequence with '+'/'*' operators evaluated strictly left to right (equal precedence) hits the target, and return a valid expression. The answer spans forward backtracking, monotonicity-based pruning, a divisibility-guided reverse search from the target, complexity analysis, and 32-bit overflow handling.
Coding & AlgorithmsTechnical Screen - PinterestMediumSoftware EngineerDelete and Compact a Forest Stored by Parent Indices
Implement subtree deletion on a parent-pointer forest array, supporting tombstoning and index compaction with pointer remapping.
Coding & AlgorithmsTechnical Screentreegrapharray - PinterestMediumSoftware EngineerDesign a violation log analyzer
This question evaluates proficiency in data structures, in-memory indexing and query design, algorithmic time/space complexity analysis, and reasoning about state management for dynamic event streams.
Coding & AlgorithmsTechnical Screen - PinterestMediumSoftware EngineerDesign adjustable ID allocator
A Pinterest software-engineer onsite coding problem: design an adjustable ID allocator over a fixed [0, 999] ID space with named, contiguous, non-overlapping bucket ranges. It covers initial allocation (packing from desired sizes and validating/normalizing proposed ranges), a resize operation that grows or shrinks a bucket by consuming adjacent free space and then minimally shifting or borrowing from neighbors under a deterministic policy, plus complexity analysis, boundary-case testing, and concurrency handling.
Coding & AlgorithmsOnsite - PinterestMediumSoftware EngineerDetermine equality of arbitrarily nested sets
This question evaluates understanding of nested data structures and set semantics, including canonicalization, hashing, recursion, handling of edge cases, unit-test design, and time/space complexity analysis.
Coding & AlgorithmsTechnical Screen
Perplexity
Pinduoduo
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