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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.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 2011–2040 of 4616 results
- IXL LearningMediumSoftware EngineerIdentify and prevent code-breaking inputs
Identify and prevent code-breaking inputs evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - IXL LearningHardSoftware EngineerMaintain a Stream Median
This question tests the ability to maintain dynamic order statistics in a streaming context, requiring an efficient way to insert elements and compute the median in logarithmic time.
Coding & AlgorithmsTechnical ScreenHeapsData StructuresAlgorithms - IXL LearningMediumSoftware EngineerSolve snake game, peak search, and task scheduling
Solve snake game, peak search, and task scheduling evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - ImcHardQuantitative TraderAnalyze Optimal Funding Allocations Across Election Districts
Analyze election-district funding games with weak-composition counting, favorable alignments, explicit allocations, and lower-bound proofs for possible and impossible wins under fixed budgets.
Statistics & MathTechnical Screen - ImcMediumSoftware EngineerAnalyze time complexity and threading trade-offs
This question evaluates understanding of worst-case time complexity for common data structure operations and the performance trade-offs between multithreading and single-threading, testing knowledge in the Software Engineering Fundamentals domain.
Software Engineering FundamentalsTechnical Screen - ImcHardQuantitative TraderCompute the Probability for Two Uniform Variables
This question evaluates understanding of continuous probability, joint distributions, and order statistics for independent uniform variables, focusing on comparing transformations of random variables.
Software Engineering FundamentalsTechnical Screen - ImcMediumSoftware EngineerDesign an in-memory hotel booking system
This question evaluates a candidate's ability to design in-memory data models, concurrency control mechanisms, and temporal reservation logic for booking systems.
System DesignTechnical Screen - ImcEasyData ScientistFind valid range of q for outcome probabilities
This question tests the ability to solve a system of linear inequalities derived from probability constraints, requiring an understanding of basic arbitrage-free pricing principles.
Software Engineering FundamentalsTechnical ScreenProbabilityInequalitiesFinance - InceptionMediumMachine Learning EngineerImplement Autoregressive Decoding in PyTorch
This question evaluates a candidate's ability to implement autoregressive decoding and sampling strategies in PyTorch, testing competencies in sequence generation, probabilistic sampling methods (greedy, temperature, top-k, top-p), batching, and end-of-sequence handling.
Machine LearningTechnical Screen - IndeedMediumSoftware EngineerCompare Arrays and Linked Lists for Indexed Operations
Compare arrays, linked lists, and unrolled lists across indexed access, insertion, allocation, cache locality, and position-search costs.
Software Engineering FundamentalsTechnical Screen - IndeedMediumSoftware EngineerImplement Get and Insert in an Unrolled Linked List
Implement indexed get and insert in an unrolled linked list, preserving block capacity, occupancy, sequence order, and split behavior.
Coding & AlgorithmsTechnical Screen - IndeedMediumMachine Learning EngineerImplement MSE Loss and Linear Regression from Scratch
Implement the mean squared error loss and a linear regression model with fit and predict methods, written from scratch rather than with a library model. It tests deriving and coding the gradients, choosing a training method, feature scaling, input validation, and verifying the implementation.
Machine LearningTechnical Screen - InstacartMediumData ScientistAggregate weekly revenue and attribute 4% drop
This question evaluates a candidate's ability to perform time-based revenue aggregation, filtering, percent-change calculation, and geo-level attribution using SQL or Python, with attention to ISO-week alignment and revenue computation.
Data Manipulation (SQL/Python)Technical Screen - InstacartMediumSoftware EngineerBuild a Progressive Banking System
This problem tests your ability to manage state transitions, handle expiring reservations, and maintain consistent ledger balances across multiple accounts.
Coding & AlgorithmsTechnical ScreenHash MapState ManagementTransaction Processing - InstacartMediumData ScientistCalculate Weekly Revenue and Order Count for Standard Deliveries
This question evaluates proficiency in time-based aggregations and filtering on order-level transactional data to compute weekly revenue and order counts specifically for standard delivery orders.
Data Manipulation (SQL/Python)Technical Screen - InstacartHardSoftware EngineerDecode a password string into letters
This problem tests your ability to parse and reconstruct a string based on specific numeric encoding rules, requiring careful index tracking and stack-based or recursive logic.
Coding & AlgorithmsTechnical ScreenStringsStackRecursion - InstacartMediumSoftware EngineerDecode an encoded string
This question evaluates string parsing and manipulation skills, particularly handling nested repetition encodings and managing state when expanding bracketed substrings.
Coding & AlgorithmsTechnical Screen - InstacartEasyData ScientistDesign a pricing experiment with network effects
This question evaluates experimental design and causal inference competencies for a two-sided marketplace pricing change, including handling network effects/interference, choice of unit of randomization and treatment markets, metric selection and diagnostics, power/MDE estimation, and operational risk assessment within the Analytics & Experimentation domain for a Data Scientist role. It is commonly asked to assess practical application of randomized and quasi-experimental methods across heterogeneous geographies and operational constraints, requiring both hands-on experimental design skills and conceptual understanding of bias, spillovers, and diagnostic metrics.
Analytics & ExperimentationTechnical Screen - InstacartMediumSoftware EngineerDesign a task system with assignments
This question tests your ability to design a flexible data model for a task-assignment system, focusing on efficient lookups and state management in an in-memory environment.
Software Engineering FundamentalsTechnical ScreenSystem DesignData StructuresAPI Design - InstacartMediumSoftware EngineerDesign an Inventory Service with Stock Reservations That Prevents Overselling
A system design discussion of an inventory service that reserves stock for orders, centered on reservations, concurrent updates and preventing overselling. It probes how stock and holds are modeled, how a reservation stays atomic under contention, how abandoned holds are released and how hot items scale.
System DesignTechnical Screen - InstacartMediumSoftware EngineerEvaluate a Target Variable from Assignments with Plus, Minus, Cycles and Conflicts
A three-part coding exercise that computes a target variable's value from a list of assignment equations. It starts with right-hand sides that are numbers or other variables, adds addition and subtraction with cross-references, and finally requires an empty string for cycles, undefined variables and conflicting assignments.
Software Engineering FundamentalsTechnical Screen - InstacartMediumSoftware EngineerEvaluate an arithmetic expression
This question tests the ability to evaluate a mathematical string containing integers, addition, subtraction, multiplication, and division, requiring an understanding of operator precedence and the use of stacks.
Coding & AlgorithmsTechnical ScreenStackParsingMath - InstacartHardSoftware EngineerEvaluate query ratios from equations
This problem tests your ability to model algebraic relationships as a weighted directed graph and perform pathfinding to calculate ratios between variables.
Coding & AlgorithmsTechnical ScreenGraphBFS/DFSMath - InstacartHardMachine Learning EngineerExplain Core ML Concepts
This question tests the conceptual understanding of supervised learning foundations, the mathematical relationship between regression techniques, and the convergence behavior of optimization algorithms.
Machine LearningTechnical ScreenLinear RegressionLogistic RegressionOptimization - InstacartMediumAI Analytics Lead IIExplain a High-Impact Analytics Project Enabled by AI
Tests your ability to present an end-to-end, AI-driven analytics project with a focus on problem framing, baseline benchmarks, guardrails, cross-functional adoption, and quantifiable business value.
Behavioral & LeadershipTechnical ScreenBehavioralAnalytics LeadershipMachine Learning - InstacartEasyData ScientistHow to debug an apparent D14 retention drop
This question evaluates competency in cohort-based retention analysis, understanding metric maturity and right-censoring, performing data quality and definition checks, and localizing real declines across segments, releases, or funnel changes.
Analytics & ExperimentationTechnical Screen - InstacartEasyData ScientistHow would you investigate a metric decline?
This question evaluates a data scientist's competency in diagnostic analytics, metric instrumentation awareness, causal reasoning, and segmentation-driven problem localization for consumer marketplace KPIs.
Analytics & ExperimentationTechnical Screen - InstacartMediumSoftware EngineerImplement multiple coding round problems
This problem tests your ability to manage a time-sensitive priority queue, handle dynamic variable substitution in expressions, and optimize for streaming data processing.
Coding & AlgorithmsTechnical ScreenHeapStackParsing - InstacartMediumData ScientistInvestigate Instacart Revenue Decline Using Weekly Data
Instacart analytics prompt on investigating a 4% weekly revenue decline, covering time-series anomaly detection, seasonality, changepoints, prediction intervals, and richer-data decomposition by orders, AOV, geography, cohorts, and categories.
Analytics & ExperimentationTechnical Screen - InstacartEasyData ScientistInvestigate marketplace metrics and experiment rollout
This question evaluates competency in marketplace analytics, causal inference, experimentation design, metric instrumentation, cohort and retention analysis, and trade-off reasoning between core business metrics and secondary signals.
Analytics & ExperimentationTechnical Screen
IXL Learning
Imc
Indeed
Instacart