Instacart interview questions

Showing 1–30 of 87 results

• Add Backend Search and Filters to the Items API of a Library Lending SystemMedium

  Implement and test backend search, multi-attribute filtering, sorting, and pagination logic for a library lending system's items catalog.

  InstacartSoftware EngineerSoftware Engineering FundamentalsOnline Assessment
• Add Hold-Available and Loan Due-Date Notifications to a Library Lending SystemMedium

  Tests domain modeling, queue management, and idempotent notification triggering for an event- and time-driven library lending workflow.

  InstacartSoftware EngineerSoftware Engineering FundamentalsOnline Assessment
• Aggregate weekly revenue and attribute 4% dropMedium

  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.

  InstacartData ScientistData Manipulation (SQL/Python)Technical Screen
• Analyze A/B test with revenue–cost tradeoffsHard

  This question evaluates a data scientist's skills in experimental design and statistical inference for A/B testing, revenue-impact modeling with skewed and zero-inflated metrics, segmentation for heterogeneous treatment effects, and constrained optimization to balance contribution and operational risk.

  InstacartData ScientistAnalytics & ExperimentationOnsite
• Answer standard behavioral questionsMedium

  How to answer the standard behavioral and leadership questions in an Instacart Software Engineer onsite using the STAR framework. Covers tell-me-about-yourself, end-to-end ownership, high-severity incidents, conflict and disagreement, failure and learning, tight deadlines with ambiguous requirements, prioritization, influencing without authority, process improvement, and your most impactful accomplishment — each with a quantified model answer.

  InstacartSoftware EngineerBehavioral & LeadershipOnsite
• Build a Progressive Banking SystemMedium

  This problem tests your ability to manage state transitions, handle expiring reservations, and maintain consistent ledger balances across multiple accounts.

  InstacartSoftware EngineerCoding & AlgorithmsTechnical Screen
• Calculate Weekly Revenue and Order Count for Standard DeliveriesMedium

  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.

  InstacartData ScientistData Manipulation (SQL/Python)Technical Screen
• Calculate a Basket Total from Delimited Product RecordsMedium

  Parse pipe-delimited shopping cart records to compute the total basket cost in integer cents, properly accumulating repeated SKUs and handling zero-quantity items.

  InstacartSoftware EngineerCoding & AlgorithmsOnsite
• Choose tests under non‑normal, unequal varianceHard

  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.

  InstacartData ScientistStatistics & MathOnsite
• Compute and optimize average wait timeMedium

  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.

  InstacartSoftware EngineerCoding & AlgorithmsOnsite
• Compute average customer waiting timeMedium

  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.

  InstacartSoftware EngineerCoding & AlgorithmsOnsite
• Compute delivery wait timesMedium

  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.

  InstacartSoftware EngineerCoding & AlgorithmsOnsite
• Compute duration and stopping rules correctlyHard

  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.

  InstacartData ScientistAnalytics & ExperimentationOnsite
• Debug Metrics Computed Before FilteringMedium

  Debug a metrics endpoint whose summary is calculated before user filters are applied even though its rows are filtered correctly. Trace the data lineage, aggregate over the full matched population before pagination, preserve security scoping, and add unit and endpoint regression tests.

  InstacartBackend EngineerSoftware Engineering FundamentalsOnline Assessment
• Debug Search and Stock Behavior in a Library ApplicationEasy

  Debug a library application’s incomplete search and stock displays by reproducing symptoms, tracing API behavior, checking query semantics, and validating focused fixes.

  InstacartSoftware EngineerSoftware Engineering FundamentalsOnline Assessment
• Decode a password string into lettersHard

  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.

  InstacartSoftware EngineerCoding & AlgorithmsTechnical Screen
• Decode an encoded stringMedium

  This question evaluates string parsing and manipulation skills, particularly handling nested repetition encodings and managing state when expanding bracketed substrings.

  InstacartSoftware EngineerCoding & AlgorithmsTechnical Screen
• Describe your most complex end-to-end projectMedium

  Describe your most complex end-to-end project evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  InstacartSoftware EngineerBehavioral & LeadershipHR Screen
• Design Idempotent Due-Date and Hold NotificationsMedium

  Design idempotent library notifications for upcoming and current due dates plus FIFO hold availability. Use stable business-event identities, transactional scheduling, atomic recipient claims, state rechecks, retries, reconciliation, and clear frontend distinctions among holds, offers, and checkouts.

  InstacartBackend EngineerSystem DesignOnline Assessment
• Design Idempotent In-App Availability and Due-Date NotificationsMedium

  Design asynchronous in-app availability alerts and due-date reminders with Celery, Redis, durable idempotency, versioned schedules, and crash recovery.

  InstacartSoftware EngineerSystem DesignOnline Assessment
• Design a bus simulation metricHard

  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.

  InstacartSoftware EngineerSoftware Engineering FundamentalsOnsite
• Design a pricing experiment with network effectsEasy

  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.

  InstacartData ScientistAnalytics & ExperimentationTechnical Screen
• Design a task system with assignmentsMedium

  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.

  InstacartSoftware EngineerSoftware Engineering FundamentalsTechnical Screen
• Design an Inventory Service with Reservations, Hot SKUs and Oversell PreventionMedium

  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.

  InstacartSoftware EngineerSystem DesignOnsite
• Design an Inventory Service with Stock Reservations That Prevents OversellingMedium

  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.

  InstacartSoftware EngineerSystem DesignTechnical Screen
• Design an inventory management systemMedium

  This question evaluates competency in system design, data modeling, distributed consistency, concurrency control, API design, idempotency, and scalability for backend inventory and reservation workflows.

  InstacartSoftware EngineerSystem DesignOnsite
• Design an inventory systemMedium

  This question evaluates a candidate's competency in designing inventory and distributed systems, covering stock tracking models, reservation and commit semantics, concurrency control, data modeling, API design, and real-time integrations.

  InstacartSoftware EngineerSystem DesignHR Screen
• Design and Interpret an A/B TestHard

  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.

  InstacartData ScientistAnalytics & ExperimentationOnsite
• Design and Release a Consistent Dark-Store Inventory SystemMedium

  Design a strongly consistent micro-fulfillment (dark-store) inventory system that handles reservations, stock reconciliation, and idempotent retries, alongside a zero-downtime deployment strategy.

  InstacartSoftware EngineerSystem DesignOnsite
• Design cloud storage with quotas and compressionHard

  This question evaluates a candidate's ability to design a multi-tenant cloud storage system, testing competencies in API design, quota accounting, compression strategies, distributed storage architecture (partitioning, replication/erasure coding), consistency models, security, versioning, and observability.

  InstacartSoftware EngineerSystem DesignOnline Assessment