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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
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- 11
- Topics
- 8
- Languages
Showing 1621–1650 of 3640 results
- InstacartMediumSoftware EngineerCalculate a Basket Total from Delimited Product Records
Parse pipe-delimited shopping cart records to compute the total basket cost in integer cents, properly accumulating repeated SKUs and handling zero-quantity items.
Coding & AlgorithmsOnsitestringsparsinghash-table - InstacartHardData ScientistChoose tests under non‑normal, unequal variance
This question tests the ability to select and justify statistical inference methods for metrics that violate standard parametric assumptions, specifically when dealing with heavy-tailed, heteroskedastic, and zero-inflated distributions.
Statistics & MathOnsiteStatisticsA/B TestingInference - InstacartMediumSoftware EngineerCompute and optimize average wait time
This question evaluates skills in scheduling and queueing algorithms, simulation of service systems, and reasoning about time and space complexity when computing average waiting times.
Coding & AlgorithmsOnsite - InstacartMediumSoftware EngineerCompute average customer waiting time
Compute average customer waiting time 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 & AlgorithmsOnsite - InstacartMediumSoftware EngineerCompute delivery wait times
This question evaluates competence in event-driven simulation, scheduling and queueing concepts, and algorithmic analysis by requiring computation of average customer waiting time for single and multiple shoppers.
Coding & AlgorithmsOnsite - InstacartHardData ScientistCompute duration and stopping rules correctly
This question evaluates a data scientist's competency in experimental design and applied statistics, specifically power and sample‑size calculations, accounting for intra‑household clustering and design effects, sequential monitoring for peeking control, and variance‑reduction or stratified randomization to handle day‑of‑week seasonality.
Analytics & ExperimentationOnsite - InstacartHardSoftware EngineerDesign a bus simulation metric
This problem tests your ability to design a telemetry metric for a simulation environment, requiring you to define efficiency, implement instrumentation within existing logic, and explain how to validate the metric's accuracy.
Software Engineering FundamentalsOnsiteSystem DesignInstrumentationSimulation - InstacartMediumSoftware EngineerDesign an Inventory Service with Reservations, Hot SKUs and Oversell Prevention
A system design question about an inventory management service that reserves stock while customers check out. It tests how a candidate prevents overselling under concurrent updates, handles hot SKUs, manages reservation expiry and idempotency, and supports partial fulfillment of multi-item orders.
System DesignOnsite - InstacartMediumSoftware EngineerDesign an inventory management system
This question evaluates competency in system design, data modeling, distributed consistency, concurrency control, API design, idempotency, and scalability for backend inventory and reservation workflows.
System DesignOnsite - InstacartHardData ScientistDesign and Interpret an A/B Test
This question tests the ability to design a statistically rigorous A/B test, calculate sample sizes based on effect thresholds, and account for real-world constraints like seasonality and multiple comparisons.
Analytics & ExperimentationOnsiteA/B TestingPower AnalysisStatistics - InstacartMediumSoftware EngineerDesign and Release a Consistent Dark-Store Inventory System
Design a strongly consistent micro-fulfillment (dark-store) inventory system that handles reservations, stock reconciliation, and idempotent retries, alongside a zero-downtime deployment strategy.
System DesignOnsitesystem-designdistributed-transactionsinventory-management - InstacartHardSoftware EngineerDesign product catalog service
This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Design product catalog service states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnsite - InstacartHardSoftware EngineerDesign scalable inventory system and avoid races
This question evaluates a candidate's ability to design scalable, highly available distributed systems with robust concurrency control and consistency reasoning, covering architecture, data modeling, caching, message-based integration, and operational concerns like observability and disaster recovery.
System DesignOnsite - InstacartMediumSoftware EngineerDiscuss an Interesting Project and a Deployment Mistake
Tests an engineer's ability to articulate complex technical architecture, evaluate architectural tradeoffs, take ownership of production failures, and demonstrate long-term operational growth.
Behavioral & LeadershipOnsitebehavioralsystem-reliabilityproduction-incidents - InstacartEasySoftware EngineerEvaluate Ordered Variable Definitions with Addition and Subtraction
Evaluate ordered variable definitions and plus/minus expressions with an explicit directional grammar, while distinguishing assignment lookup from general equation solving.
Coding & AlgorithmsOnsite - InstacartMediumSoftware EngineerEvaluate a Variable from Chained Assignments with +/- Expressions and Cycle Detection
A coding problem that evaluates a target variable from chained assignments such as T1 = T2 and T2 = 5, then extends to right-hand sides with plus and minus and to inputs that may contain cycles. It tests parsing, memoized dependency resolution and cycle detection that does not flag shared dependencies.
Software Engineering FundamentalsOnsite - InstacartMediumSoftware EngineerEvaluate arithmetic expression with precedence
Instacart software-engineer onsite coding question: implement an arithmetic expression evaluator for a string of non-negative integers, +, -, *, /, parentheses, and spaces. It tests operator precedence and associativity, unary minus, 64-bit intermediates, integer division truncating toward zero, and robust handling of invalid input via a two-stack, shunting-yard, or recursive-descent parser.
Coding & AlgorithmsOnsite - InstacartMediumSoftware EngineerEvaluate dependent variable expressions
This question evaluates a candidate's ability to parse and evaluate assignment expressions, resolve inter-variable dependencies, and detect cycles or unsolvable references.
Coding & AlgorithmsOnsite - InstacartMediumSoftware EngineerExplain Technical Tradeoffs in a Project You Led
Discuss a led project through concrete technical alternatives, implementation details, personal ownership, coordination, and supported outcomes.
Behavioral & LeadershipOnsite - InstacartMediumSoftware EngineerExplain your biggest project with trade-offs
This question evaluates technical leadership, system-design trade-off analysis, communication, and conflict-resolution competencies by probing a candidate's most impactful project, role, technical design choices, and a real teammate disagreement.
Behavioral & LeadershipOnsite - InstacartMediumSoftware EngineerImplement a pivot table transformation
This question evaluates competency in data transformation and aggregation, specifically pivot operations, time-based grouping, null handling, dimensionality reduction (top‑K/OTHER), scalability for large datasets, and expressing solutions in both Python (pandas or pure) and SQL within the Data Manipulation (SQL/Python) domain.
Data Manipulation (SQL/Python)Onsite - InstacartMediumSoftware EngineerImplement bus route simulation features
This question evaluates a candidate's skills in stateful event-driven simulation, data-structure and algorithm design for capacity-constrained boarding and dropping logic, and statistical downsampling to preserve origin–destination demand distributions.
Coding & AlgorithmsOnsite - InstacartMediumSoftware EngineerImplement matrix-indexing and expression resolver
This question evaluates a candidate's ability to parse structured text files, perform matrix indexing with a nonstandard origin convention, reconstruct data across multiple blocks, and resolve symbolic variable expressions and dependencies for arithmetic evaluation in the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - InstacartHardSoftware EngineerImplement store, evaluator, and parser
This problem tests your ability to design a robust in-memory data store with versioning and TTL, implement an expression evaluator for dependencies, and parse a specialized stream of matrix data.
Coding & AlgorithmsOnsiteData StructuresHashingRecursion - InstacartHardData ScientistImprove low R² without p‑hacking
This question evaluates competence in statistical modeling and causal inference, covering regression diagnostics, feature engineering and interactions, appropriate error distributions and link functions, leakage detection, model selection and validation, and the trade-off between predictive accuracy and valid effect estimation.
Machine LearningOnsite - InstacartMediumSoftware EngineerMake a Variable Resolver Safe for Production Use
Analyze variable-resolution complexity and improve stack safety, validation, cycle detection, error reporting, caching, and update consistency.
Software Engineering FundamentalsOnsite - InstacartMediumSoftware EngineerParse Pipe-Delimited Order Lines: Totals, Cheapest Promotion per SKU, Aisle Ordering
A three-part coding exercise that parses pipe-delimited order lines with prices in cents, applies the cheapest of several percentage and buy-X-get-Y promotions per SKU, and orders products by aisle with frozen items last. It tests input validation, exact money arithmetic, extensible pricing rules and composite sorting.
Software Engineering FundamentalsOnsite - InstacartMediumSoftware EngineerParse a password from a matrix
This question evaluates proficiency in grid traversal, sequence-driven state tracking, string manipulation, and boundary/obstacle validation while requiring time and space complexity reasoning.
Coding & AlgorithmsOnsite - InstacartMediumSoftware EngineerParse password from indexed matrix file
This question evaluates file parsing, matrix indexing with a specified coordinate origin, handling multiple indexed blocks, and string assembly into an ordered password, testing competencies in file I/O, coordinate transformations, and robust input handling.
Coding & AlgorithmsOnsite - InstacartMediumSoftware EngineerPivot data without date libraries
This question evaluates a candidate's competency in data manipulation and transformation, specifically pivoting tall datasets into wide views, handling missing metric values, ordering ISO date strings via string operations, and meeting algorithmic efficiency constraints (O(n log n)).
Data Manipulation (SQL/Python)Onsite
Instacart