practice a little every day, paws crossed ♡
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 2851–2880 of 3640 results
- PinterestMediumMachine Learning EngineerSolve Expression and Tree-List Problems
This problem tests recursive backtracking for expression generation and pointer manipulation for in-place tree-to-linked-list conversion.
Coding & AlgorithmsOnsiteBacktrackingTreesLinked Lists - PinterestMediumSoftware EngineerSolve Four Interview Coding Problems
This set tests proficiency in graph algorithms, binary search on sorted data, grid simulations, and custom data structure design for real-time leaderboards.
Coding & AlgorithmsOnsiteGraphsBinary SearchSimulation - PinterestMediumMachine Learning EngineerSolve five hard algorithm problems
This problem tests your ability to optimize range-based operations using a difference array or prefix sum strategy and demonstrates your skill in balancing computational efficiency with memory constraints.
Coding & AlgorithmsOnsiteArraysPrefix SumDifference Array - PinterestMediumMachine Learning EngineerSolve prefix, array, and string problems
This problem tests your ability to efficiently manage prefix-based string searching using a Trie data structure, specifically focusing on handling wildcard character matching.
Coding & AlgorithmsOnsiteTrieStringRecursion - PinterestMediumSoftware EngineerSolve set equality and ad log top‑K
This multi-part question evaluates set and multiset operations, frequency counting, top-K computation over time windows, sliding-window and streaming data structures, and character-multiset matching for string construction within the coding & algorithms domain.
Coding & AlgorithmsOnsite - PinterestHardMachine Learning EngineerSupport room moves and query top-k fastest
This problem tests your ability to design a data structure that efficiently manages room assignments and retrieves the top-k rooms based on a primary priority (number of people) and a secondary priority (earliest arrival time).
Coding & AlgorithmsOnsiteData StructuresHeapHash Map - PinterestMediumSoftware EngineerTrack a User's Top Trending Viewed Pin Within a Sliding Time Window
A data structure design exercise: track the Pins a user has viewed within a sliding time window and, at any moment, return the one with the highest trending score. It asks for methods to add a viewed Pin, remove expired Pins and query the top Pin, plus the runtime complexity of each operation.
Software Engineering FundamentalsOnsite - PinterestMediumData ScientistTransform nested dicts with pandas apply/lambda
This question evaluates proficiency in pandas-based data manipulation, including flattening nested list and dict structures, parsing nested attributes, computing per-user aggregates and segment metrics, and implementing robust, vectorized extraction logic that handles missing keys and avoids SettingWithCopy pitfalls.
Data Manipulation (SQL/Python)Onsite - PinterestHardData ScientistVerify Machine-Learning Fundamentals for E-commerce Recommendation Platform
This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Verify Machine-Learning Fundamentals for E-commerce Recommendation Platform states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningOnsite - PinterestMediumData ScientistWrite SQL to compute max-overlap lists
This question evaluates proficiency in SQL data manipulation and set-based operations, focusing on deduplication, pairwise aggregation, and similarity metric computation (Jaccard) over relational tables.
Data Manipulation (SQL/Python)Onsite - PinterestMediumData ScientistWrite SQL to rank categories by impressions
This question evaluates proficiency in SQL data manipulation—covering joins, aggregations, grouping, tie-breaking, date-window logic, and scalability considerations such as indexing and query performance—in the Data Manipulation (SQL/Python) domain.
Data Manipulation (SQL/Python)Onsite - PinterestMediumData ScientistWrite windowed retention and ARPU SQL
This question evaluates proficiency with SQL window functions, joins, aggregations and time-windowed analytics for computing retention and ARPU, as well as handling date truncation, UTC day boundaries and common data edge cases across user, session, and order tables.
Data Manipulation (SQL/Python)Onsite - PitchbookEasySoftware EngineerImplement Euclidean distance and k-nearest neighbors
This question evaluates understanding of Euclidean distance metrics, vector arithmetic, and nearest-neighbor retrieval, testing implementation skills for computing distances and selecting the k closest points.
Coding & AlgorithmsOnsite - PlaidMediumMachine Learning EngineerDesign RAG Evaluation and Debugging
Design a comprehensive evaluation, monitoring, and debugging framework for a production Retrieval-Augmented Generation (RAG) system operating in a high-stakes financial data domain. The candidate must address multi-stage metrics, CI/CD regression testing, and root-cause localization for retrieval vs. generation failures.
ML System DesignOnsiteRAGLLM EvaluationModel Monitoring - PlaidMediumSoftware EngineerDesign an Embeddable Pay by Bank Widget
Design a secure, embeddable Pay by Bank frontend widget and supporting backend infrastructure that enables direct bank checkout via an isolated iframe and asynchronous payment processing.
System DesignOnsiteSecurityWeb ArchitecturePayments - PlaidMediumSoftware EngineerExplain What You Seek and an Unexpected Project Outcome
Tests candidate self-awareness, career motivation, and adaptability when technical initiatives diverge from expectations due to real-world constraints.
Behavioral & LeadershipOnsiteBehavioralCareer GoalsAdaptability - PlaidMediumSoftware EngineerReason About Rate Limiting Under Memory and Throughput Pressure
Tests the candidate's ability to design a high-throughput, memory-bounded rate limiter using bucketed counters instead of unbounded timestamp queues, balancing concurrency, memory overhead, and precision.
Software Engineering FundamentalsOnsiteRate LimitingConcurrencyData Structures - Point72MediumData ScientistExplain How L1 and L2 Regularization Change Linear-Model Coefficients
This question tests the conceptual understanding of how L1 and L2 penalties influence the optimization objective and the resulting structure of the weight vector in a linear regression model.
Machine LearningOnsiteRegularizationLinear RegressionOptimization - PurestorageMediumSoftware EngineerDesign a thread-safe event dispatcher
This question evaluates understanding of concurrent programming and thread-safe design, including synchronization primitives, race-condition avoidance, listener lifecycle semantics, and event-delivery guarantees.
Software Engineering FundamentalsOnsite - PurestorageMediumSoftware EngineerDetermine whether points form squares
This question evaluates computational geometry, combinatorial counting, and algorithmic optimization skills by requiring validation of a non-degenerate square from four 2D integer points and counting distinct squares in a larger point set, and it falls under the Coding & Algorithms category.
Coding & AlgorithmsOnsite - Qualified HealthHardSoftware EngineerControl LLM Workflow Quotas and Recovery Costs
Control LLM workflow quotas and 429 retries with shared token budgets, durable checkpoints, and explicit handling of uncertain requests and duplicate billing.
System DesignOnsite - Qualified HealthHardSoftware EngineerEnforce Tenant and Session Isolation in an Agent RAG System
Isolate tenants and sessions across RAG retrieval, caches, prompts, and tools, with server-enforced authorization and layered prompt-injection defenses.
System DesignOnsite - Qualified HealthHardSoftware EngineerIngest and Serve RAG Sessions with Up to 200 Documents
Design a 200-document RAG session pipeline with asynchronous ingestion, corpus readiness, latency budgeting, scoped caching, and quota-aware serving.
System DesignOnsite - Qualified HealthHardSoftware EngineerReconcile RAG Document Expiry, Chat History, and Cold Audits
Design 24-hour document deletion, seven-day chat history, fast sidebar reads, and cold audits while resolving conflicts over derived content and physical erasure.
System DesignOnsite - Qualified HealthHardSoftware EngineerRecover Durable Workflows with External Effects and Long Waits
Recover DAG workflows through crashes, duplicate attempts, external side effects, and multi-day approvals using durable state and explicit exactly-once limits.
System DesignOnsite - Qualified HealthHardSoftware EngineerScale Mixed I/O and LLM Workflow Execution
Scale mixed I/O and LLM workflows with separate worker budgets, tenant fairness, tiered state storage, and explicit reconciliation of conflicting workload figures.
System DesignOnsite - Qualified HealthHardSoftware EngineerStream LLM Output While Committing Reliable DAG Results
Stream provisional LLM output to clients while durably validating and committing complete structured results before downstream DAG tasks execute.
System DesignOnsite - Qualified HealthHardSoftware EngineerStream and Cancel Agent Responses Without Unsafe Retries
Design SSE or WebSocket streaming, end-to-end stop handling, and safe Agent retries while distinguishing local cancellation from provider billing and tool effects.
System DesignOnsite - Qualified HealthHardSoftware EngineerValidate Editable DAGs and Bound Runtime Repetition
Validate editable workflow DAGs, reason about cycle-check latency, and enforce durable retry and expansion limits that prevent unbounded runtime loops.
System DesignOnsite - RampHardSoftware EngineerBuild a Resilient Chain of Clue-Driven HTTP Requests
Implement a resilient HTTP traversal client that follows a sequence of clue-bearing API responses to reach a final payload while enforcing safety policies like loop detection, retry budgets, deadline management, response size caps, and origin-scoped auth tokens.
Software Engineering FundamentalsOnsitehttpnetworkingdistributed-systems
Pinterest
Plaid
Point72
Ramp