Pinterest interview questions

Showing 91–120 of 161 results

• Hierarchical Access Control for an Advertising PlatformMedium

  This problem tests graph traversal algorithms and efficient membership checking within a directed acyclic graph (DAG) representing hierarchical organizational permissions.

  PinterestMachine Learning EngineerCoding & AlgorithmsOnsite
• How to Design a Proportional Randomized Sampler?Medium

  This question evaluates proficiency in randomized algorithms and probabilistic sampling, with emphasis on numerical precision, large-weight handling, and memory-versus-accuracy trade-offs. Commonly asked in Coding & Algorithms interviews for data-science roles, it assesses practical application ability grounded in conceptual understanding of numerical stability and relevant data-structure choices.

  PinterestData ScientistCoding & AlgorithmsOnsite
• How to evaluate a new Carousel featureEasy

  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.

  PinterestData ScientistAnalytics & ExperimentationTechnical Screen
• How would you evaluate a carousel launch?Medium

  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.

  PinterestData ScientistAnalytics & ExperimentationTechnical Screen
• Implement Binary Search for Policy Violation LogsMedium

  This question evaluates understanding of algorithmic search and data manipulation skills, specifically applying binary search over date-ordered logs and composing efficient queries using SQL and Python.

  PinterestData ScientistData Manipulation (SQL/Python)Onsite
• Implement Bootstrap and Jackknife Estimates on a DataFrameMedium

  Tests practical statistical computing skills by requiring the implementation of bootstrap confidence intervals and jackknife variance estimation for arbitrary metrics evaluated on pandas DataFrames.

  PinterestData ScientistStatistics & MathOnsite
• Implement Data Structure for Top-K Elements in StreamsMedium

  This question evaluates competency in streaming algorithms, dynamic data structures for maintaining top-K elements in real time, and scalability considerations for handling large or distributed input streams.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Implement Function to Return First n Prime NumbersMedium

  This question evaluates algorithmic problem-solving and basic number-theory competency by requiring generation of prime numbers with attention to correctness and performance characteristics.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Implement Hierarchical Region Access OverridesMedium

  Design and implement a regional access control system that handles time-based access overrides on a static tree hierarchy with out-of-order updates.

  PinterestSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• Implement Jackknife and Random ChoiceMedium

  Implement weighted random selection from scratch and compute delete-1 jackknife estimates of parameter bias and standard error for an arbitrary statistical estimator.

  PinterestData ScientistCoding & AlgorithmsTechnical Screen
• Implement LRUCache with O(1) Operations and Thread SafetyMedium

  This question evaluates a candidate's ability to implement a constant-time LRU cache and reason about thread-safety and concurrent access, testing data structure design and concurrency competencies in the Coding & Algorithms domain.

  PinterestData ScientistCoding & AlgorithmsOnsite
• Implement Naive Bayes classifier from scratchHard

  This question evaluates understanding of probabilistic classification, specifically competence in estimating class priors, feature likelihood parameters, and computing posterior scores for Naive Bayes variants.

  PinterestMachine Learning EngineerMachine LearningOnline Assessment
• Implement a Sparse Matrix ClassMedium

  Design and implement a memory-efficient sparse matrix class supporting entry retrieval, updates, addition, and matrix multiplication.

  PinterestMachine Learning EngineerCoding & AlgorithmsTechnical Screen
• Implement a Stateful Search Autocomplete SessionHard

  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.

  PinterestMachine Learning EngineerCoding & AlgorithmsTechnical Screen
• Implement a min-heap column allocatorMedium

  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.

  PinterestSoftware EngineerCoding & AlgorithmsTechnical Screen
• Implement and Evaluate Pin Similarity in PythonHard

  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.

  PinterestData ScientistData Manipulation (SQL/Python)Technical Screen
• Implement and extend My Calendar IIIMedium

  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.

  PinterestData ScientistCoding & AlgorithmsTechnical Screen
• Implement bagging with decision treesHard

  This question evaluates a candidate's competency in ensemble learning and practical implementation skills, including bootstrap sampling, decision tree base learners, aggregation via majority voting with tie-breaking, and managing data using pure Python lists and standard library routines.

  PinterestMachine Learning EngineerMachine LearningOnline Assessment
• Implement np.random.choiceEasy

  This problem tests your ability to implement weighted random sampling from an array, focusing on probability distribution handling and efficient selection algorithms.

  PinterestData ScientistCoding & AlgorithmsTechnical Screen
• Implement sparse matrix storage, addition, and multiplicationMedium

  This problem tests your ability to design a memory-efficient representation for sparse matrices and implement arithmetic operations while leveraging the sparsity of the data.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Implement stream line reader and settle balancesMedium

  This question evaluates streaming I/O and buffered string-processing competency for Part 1 and transaction netting with balance computation for Part 2, covering skills in memory-bounded parsing, data-structure bookkeeping, and algorithmic flow reasoning.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Implement string-based big integer multiplicationMedium

  Implement multiplyStrings(a, b) to multiply two non-negative integers given as decimal strings, returning the product as a string without any big-integer or arbitrary-precision library. The solution covers grade-school O(n*m) long multiplication with linear memory, the Karatsuba and FFT/NTT scaling alternatives, correct carry and leading/trailing-zero handling, and a full edge-case test plan.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Implement string-based rounding without floatsEasy

  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.

  PinterestMachine Learning EngineerCoding & AlgorithmsTechnical Screen
• Implement tap-to-infect color grid on iOSMedium

  This question evaluates proficiency in mobile UI architecture, grid data structures, connected-component algorithm reasoning, and state management concerns such as undo and memory/stack safety within the mobile app development and iOS domain.

  PinterestSoftware EngineerSoftware Engineering FundamentalsOnsite
• Implement trie-based autocompleteHard

  This problem tests your ability to implement a space-efficient Trie data structure capable of storing strings along with associated weights to return top-k suggestions for a given prefix.

  PinterestMachine Learning EngineerCoding & AlgorithmsOnsite
• Implement weighted random choiceMedium

  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.

  PinterestData ScientistCoding & AlgorithmsTechnical Screen
• Insert Operators to Reach a TargetMedium

  Tests backtracking with operator precedence handling and operand formatting to construct all valid arithmetic expressions evaluating to a target value.

  PinterestSoftware EngineerCoding & AlgorithmsOnsite
• Interpret A/B results for video-pin increaseMedium

  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.

  PinterestData ScientistAnalytics & ExperimentationTechnical Screen
• Investigate Homepage Experiment Without Control Group: Methods and MetricsHard

  Evaluates quasi-experimental analysis and product-metric judgment after a homepage launch lacks a randomized control. Strong answers compare matching and propensity weighting, audit experiment hygiene, choose metrics, and diagnose mixed CTR results.

  PinterestData ScientistAnalytics & ExperimentationOnsite
• Keep Merchant Addresses, Social Followers, and Wiki Facts Up to DateHard

  Design a high-scale merchant data enrichment platform that ingests, reconciles, and maintains up-to-date business attributes (addresses, social metrics, wiki metadata) across heterogeneous third-party sources with strong provenance and fault tolerance.

  PinterestSoftware EngineerSystem DesignOnsite