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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.
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Showing 3271–3300 of 4616 results
- PinterestEasyMachine Learning EngineerExplain learning-rate fluctuation and vanishing gradients
This question evaluates a candidate's understanding of optimization dynamics (effects of learning rate on training stability) and backpropagation-related issues (vanishing gradients) in deep neural networks, assessing competencies in training behavior and gradient propagation within the Machine Learning domain.
Machine LearningTechnical Screen - PinterestHardMachine Learning EngineerExplain overfitting and how to prevent it
This question evaluates understanding of overfitting, the relationship between training and validation performance and generalization, and knowledge of regularization concepts including differences between L1 and L2 penalties.
Machine LearningTechnical Screen - PinterestHardMachine Learning EngineerExplain overfitting, underfitting, and regularization
This question tests the conceptual understanding of the bias-variance tradeoff and the practical application of regularization to balance model complexity and generalization error.
Machine LearningTechnical ScreenBias-VarianceRegularizationGeneralization - PinterestHardData ScientistExplain your ML project end-to-end
This question evaluates a data scientist's end-to-end machine learning competencies, including problem framing and metric justification, data sourcing and labeling, model selection and calibration, class-imbalance handling, deployment and monitoring, experimentation design, and post-mortem analysis; it is in the Machine Learning domain and tests both conceptual understanding and practical application across modeling and MLOps. It is commonly asked to assess an interviewee's ability to justify trade-offs, reason about operational constraints such as latency, fairness and cost, design valid evaluation and A/B testing strategies, and define measurable monitoring and rollback criteria.
Machine LearningTechnical Screen - PinterestEasySite Reliability EngineerFetch a Field from Two URLs, Extract Valid IP Addresses, and Rank Them by Count
A practical scripting exercise for a site reliability role: send GET requests with a required header to two URLs, pull a text field from each response, extract every valid IP address, and rank the addresses by how often they appear. It tests HTTP error handling, strict IPv4 validation, code reuse and deterministic sorting.
Software Engineering FundamentalsTechnical Screen - PinterestMediumSoftware EngineerFind First Prefix-Matching Word
This problem tests your ability to efficiently search through a collection of strings to find the first element that satisfies a specific prefix condition, emphasizing clean iteration and edge case management.
Coding & AlgorithmsTechnical ScreenStringsArraysIteration - PinterestMediumData ScientistFind the Share of Power Listeners per Region from Play Events
Write a PostgreSQL query that, for a trailing 7-day window, classifies listeners per region as active or 'power' users based on how many distinct days they listened and whether they used at least three different playback devices on any single one of those days, then reports the power-user share per region.
Data Manipulation (SQL/Python)Technical Screensqlwindow-functionsaggregation - PinterestMediumData ScientistFind top video category by average time
This question evaluates a candidate's ability to perform data manipulation and aggregation in Python (pandas), covering skills such as filtering, handling nulls and nonpositive values, mapping categorical IDs to names, rounding numerical results, and applying tie-breaking rules.
Data Manipulation (SQL/Python)Technical Screen - PinterestMediumSoftware EngineerGenerate Attribute Combinations
Explain Cartesian-product generation for attribute choices while preserving mixed value types and making ordering, duplicates, and empty cases explicit.
Software Engineering FundamentalsTechnical Screen - PinterestMediumMachine Learning EngineerGenerate all hyperparameter combinations
This problem tests your ability to generate the Cartesian product of multiple lists, a fundamental task in grid search for hyperparameter tuning.
Coding & AlgorithmsTechnical ScreenCombinatoricsRecursionIteration - PinterestEasyData ScientistHow to evaluate a new Carousel feature
This question tests your ability to design an A/B test for a feed-based UI feature, focusing on metric selection, counter-metrics, and the identification of potential cannibalization effects.
Analytics & ExperimentationTechnical ScreenA/B TestingMetricsExperiment Design - PinterestMediumData ScientistHow would you evaluate a carousel launch?
This question tests your ability to design a comprehensive evaluation framework for a product feature launch, specifically focusing on metric selection, causal impact measurement, and addressing potential cannibalization effects.
Analytics & ExperimentationTechnical ScreenExperimentationMetricsProduct Analytics - PinterestMediumSoftware EngineerImplement Hierarchical Region Access Overrides
Design and implement a regional access control system that handles time-based access overrides on a static tree hierarchy with out-of-order updates.
Software Engineering FundamentalsTechnical ScreenTreeBinary SearchData Structures - PinterestMediumData ScientistImplement Jackknife and Random Choice
Implement weighted random selection from scratch and compute delete-1 jackknife estimates of parameter bias and standard error for an arbitrary statistical estimator.
Coding & AlgorithmsTechnical Screensamplingresamplingstatistics - PinterestMediumMachine Learning EngineerImplement a Sparse Matrix Class
Design and implement a memory-efficient sparse matrix class supporting entry retrieval, updates, addition, and matrix multiplication.
Coding & AlgorithmsTechnical Screensparse-matrixhash-tablelinear-algebra - PinterestHardMachine Learning EngineerImplement a Stateful Search Autocomplete Session
Design an interactive autocomplete system that tracks query frequencies, returns the top 3 ranking prefix matches per keystroke, and commits completed queries to dynamic history.
Coding & AlgorithmsTechnical ScreenTrieHash TableDesign - PinterestMediumSoftware EngineerImplement a min-heap column allocator
This question evaluates a candidate's competency in data structures (priority queues/min-heaps), online algorithm design for stream processing, and complexity and memory analysis.
Coding & AlgorithmsTechnical Screen - PinterestHardData ScientistImplement and Evaluate Pin Similarity in Python
Practice a DS-focused Python similarity question using Pin representations, cosine similarity, top-k ranking, and explicit edge-case handling. Extend the implementation discussion to vectorized scaling, approximate retrieval, offline ranking metrics, leakage checks, diversity, and online evaluation.
Data Manipulation (SQL/Python)Technical Screen - PinterestMediumData ScientistImplement and extend My Calendar III
This question evaluates competency in designing and implementing efficient dynamic interval data structures, handling correctness for duplicate and nested intervals, extending APIs with cancellation and point queries, and performing rigorous worst-case time/space analysis and resource-adaptation.
Coding & AlgorithmsTechnical Screen - PinterestEasyData ScientistImplement np.random.choice
This problem tests your ability to implement weighted random sampling from an array, focusing on probability distribution handling and efficient selection algorithms.
Coding & AlgorithmsTechnical ScreenProbabilitySamplingAlgorithms - PinterestEasyMachine Learning EngineerImplement string-based rounding without floats
This question evaluates proficiency in string-based numeric processing, arbitrary-precision arithmetic concepts, precise rounding rules including deterministic tie-breaking, and handling of sign and decimal edge cases, and falls under the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - PinterestMediumData ScientistImplement weighted random choice
This problem tests your ability to implement efficient weighted random selection, specifically focusing on cumulative distribution functions and binary search to achieve optimal query performance.
Coding & AlgorithmsTechnical ScreenAlgorithmsProbabilityBinary Search - PinterestMediumData ScientistInterpret A/B results for video-pin increase
This question evaluates statistical inference and experimentation skills, including A/B test hypothesis formulation with a predefined MDE, estimation of absolute and relative lift with confidence intervals, proportion testing for CTR and retention, sample ratio mismatch detection, and multiple-comparison adjustments.
Analytics & ExperimentationTechnical Screen - PinterestMediumSoftware EngineerList Unallocated Experiment Buckets
Determine all unassigned experiment bucket IDs in the range [0, total_buckets - 1] given lists of control and treatment bucket allocations.
Coding & AlgorithmsTechnical Screenarrayhash-tablebit-manipulation - PinterestHardMachine Learning EngineerPrevent Vanishing Gradients in Deep Networks
Tests a candidate's mathematical understanding of the vanishing gradient problem in deep neural networks and their ability to evaluate architectural mitigations including weight initialization, activation functions, residual connections, and normalization layers.
Machine LearningTechnical ScreenDeep LearningOptimizationNeural Networks - PinterestMediumSoftware EngineerRebalance Experiment Buckets with Minimal Reassignment
Implement a deterministic rebalancing algorithm that redistributes entities among experiment buckets to meet exact target counts while minimizing reassignments and applying canonical tie-breaking.
Coding & AlgorithmsTechnical Screengreedysortinghash-map - PinterestMediumSoftware EngineerReconstruct an Itinerary While Keeping an Unspecified Variant Explicit
Tests finding an Eulerian path in a directed multigraph with lexicographical tie-breaking using Hierholzer's algorithm.
Software Engineering FundamentalsTechnical Screengraphdfseulerian-path - PinterestMediumSoftware EngineerReconstruct itinerary with lexicographic ties
This question evaluates a candidate's ability to model and traverse directed graphs with repeated edges, enforce lexicographic ordering among possible paths, and analyze time and space complexity for an algorithmic solution.
Coding & AlgorithmsTechnical Screen - PinterestMediumSoftware EngineerRemove and Compact a Parent-Index Forest
Tests tree traversal to find subtrees, array compaction, and index remapping on a parent-pointer forest representation without mutating input data.
Coding & AlgorithmsTechnical Screentreearraybfs - PinterestMediumSoftware EngineerRound numeric string values
This question evaluates parsing and numeric manipulation skills, specifically implementing rounding rules for numeric strings and handling decimals, significant digits, and precision edge cases.
Coding & AlgorithmsTechnical Screen
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