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Data Manipulation (SQL/Python) 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 91–120 of 256 results

  • GustoMediumData Scientist
    Calculate Net Pay Change for Q1 2023 Decreases

    This question evaluates a candidate's data-manipulation competency in SQL and Python, focusing on computing net pay, aggregating over a calendar quarter, and measuring percentage change between recent pay periods.

    Data Manipulation (SQL/Python)Technical Screen
  • InstacartMediumData Scientist
    Aggregate 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
  • InstacartMediumData Scientist
    Calculate 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
  • InstacartMediumData Scientist
    Write SQL to rank advertisers and profitability

    This question evaluates a candidate's ability to perform ANSI SQL data transformations including unpivoting denormalized tables, aggregations, joins, and financial metric calculations such as net profit and profit margin while handling nulls and tie-breaking rules.

    Data Manipulation (SQL/Python)Technical Screen
  • IntuitMediumData Scientist
    Compute monthly new subscribers and YoY deltas

    This question evaluates proficiency in SQL time-series aggregation and cohort identification, including generating a month spine, computing year-over-year deltas, handling nulls and division-by-zero, and identifying partial months via a data watermark.

    Data Manipulation (SQL/Python)Technical Screen
  • IntuitMediumData Scientist
    Exclude free subscribers via anti-join

    This question evaluates competency with SQL anti-joins, join semantics, deduplication, and correct pre-aggregation filtering to prevent excluded entities from affecting aggregated monthly and year-over-year metrics; it is categorized as Data Manipulation (SQL/Python) for a Data Scientist role.

    Data Manipulation (SQL/Python)Technical Screen
  • IntuitMediumMachine Learning Engineer
    Longest Meeting-Free Business-Hours Block per Employee and Day

    Find each employee’s longest meeting-free business-hours interval using clipped attendance, merged overlaps, complete day coverage, and SQL window logic.

    Data Manipulation (SQL/Python)Technical Screen
  • IntuitEasyData Scientist
    Pivot daily users and revenue by platform

    This question evaluates data manipulation and aggregation skills, specifically computing distinct user counts and revenue aggregates and reshaping results by platform; it is in the Data Manipulation (SQL/Python) domain and assesses practical application rather than purely conceptual understanding.

    Data Manipulation (SQL/Python)Technical Screen
  • KikoffMediumSoftware Engineer
    Parse CSV and format transactions

    This question evaluates a candidate's ability to parse and format structured transactional data, emphasizing CSV parsing, trimming whitespace, numeric formatting to two decimal places, and preserving input row order.

    Data Manipulation (SQL/Python)Technical Screen
  • LendingClubMediumData Scientist
    Query Active Loans by Borrower ID in SQL

    This question evaluates proficiency with SQL data aggregation, grouping, and ordering to compute borrower-level loan totals, assessing practical skills in relational data manipulation within the Data Manipulation (SQL/Python) domain.

    Data Manipulation (SQL/Python)Technical Screen
  • LinkedInEasyData Scientist
    Analyze member video posting behavior by country

    A LinkedIn data scientist technical-screen question on member video-posting behavior using two relational tables. It tests joins, first-event derivation with MIN/GROUP BY, conditional grouping for US vs non-US comparison, and distinct-member counts per country with a length filter.

    Data Manipulation (SQL/Python)Technical Screen
  • LinkedInEasyData Scientist
    Compute each member’s current notification status

    A LinkedIn data scientist SQL screen: given an end-of-January notification-status snapshot and a February log of turn_on/turn_off actions, compute each member's current status as of 2020-02-29, keeping members from either table. Follow-ups explore reconstructing state when the action log has no date column — unsolvable in general, but recoverable via action-count parity when every action is a guaranteed valid transition.

    Data Manipulation (SQL/Python)Technical Screen
  • LinkedInMediumData Scientist
    Count Article Types Viewed

    Count Article Types Viewed evaluates SQL or pandas logic, joins, grouping, window functions, null handling, edge cases, and validation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Data Manipulation (SQL/Python)Technical Screen
  • LinkedInMediumData Scientist
    Device Status without Timestamps

    This question evaluates data manipulation and behavioral analytics competencies, emphasizing aggregation, deduplication, distinct counts, and date-based filtering to measure author and viewer activity.

    Data Manipulation (SQL/Python)Technical Screen
  • LinkedInMediumData Scientist
    [SQL] Job Ad Metrics with Applicant Filter

    This question evaluates proficiency in SQL data manipulation and deduplication, focusing on aggregations, distinct counts, and conditional filtering of event records (views vs applies).

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Analyze Bookstore Data to Identify Top Payment Methods

    This question evaluates data manipulation and analytical SQL/Python competency, focusing on relational joins, aggregations, string filtering, ranking, and proportion calculations across multiple tables in a bookstore schema.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Analyze Mobile Promo Orders with SQL Query and Metrics

    This question evaluates SQL data-manipulation and analytical competencies, including filtered joins, conditional aggregation, date-window filtering, and business-metric design to measure promotional performance on mobile orders.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Analyze Seller Activity and Vehicle Listing Interactions

    This interview question evaluates SQL or pandas logic, joins, grouping, window functions, null handling, edge cases, and validation in a realistic interview setting. A strong answer for Analyze Seller Activity and Vehicle Listing Interactions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Analyze Social Media Engagement with SQL Queries

    This question evaluates SQL data-manipulation and analytics competencies, including aggregation, DISTINCT counting, joins between view and action logs, date-range filtering, and conditional metric computation from event data.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Analyze Top Call Initiators and Active French Video Callers

    This question evaluates proficiency in SQL-based data manipulation and analytics—specifically aggregation, grouping, time-window filtering, and percentage calculations—by asking for the top call initiators over the last seven days and the proportion of active users in France on video calls yesterday, and is categorized under Data Manipulation (SQL/Python) for a Data Scientist role with a focus on practical application. It is commonly asked in technical interviews to assess a data scientist's ability to extract actionable engagement metrics from event logs, reason about temporal windows and population denominators, and produce accurate, explainable reporting from production-style datasets.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Analyze User Engagement and Spammer Read-Rate in SQL

    This question evaluates SQL-based data manipulation and analytics skills—specifically joins, time-window filtering, aggregation, and metric calculation for measuring user engagement and spammer read-rate—within the Data Manipulation (SQL/Python) domain.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Calculate CTR and ad revenue

    This problem tests your ability to clean and join datasets, handle currency conversion, and aggregate metrics at different granularities.

    Data Manipulation (SQL/Python)Technical ScreenSQLData AggregationMetrics
  • MetaMediumData Scientist
    Calculate Daily Survey Response Rates by Country

    Write a PostgreSQL query to compute daily survey response rates at the country level using distinct user counts while handling orphan response logs and edge cases.

    Data Manipulation (SQL/Python)Technical ScreenSQLPostgreSQLData Aggregation
  • MetaMediumData Scientist
    Calculate French User Engagement and U.S. Call Duration

    This question evaluates proficiency in SQL-based data manipulation and analytics, testing skills such as joining event and profile tables, aggregating metrics, and computing user-level engagement proportions and average durations.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Calculate Survey Response Rate and Quality Metric in SQL

    This question evaluates SQL data-manipulation competencies such as aggregation, NULL handling, deduplication (first-per-group), and computing engagement and quality metrics from event logs.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Calculate Video Call Usage Metrics by Country and Date

    This question evaluates data manipulation and product-analytics skills, focusing on joining user and call datasets, aggregations for distinct-user percentages, and per-DAU duration calculations.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Compare Survey Satisfaction for New and Established Users

    Tests your ability to write PostgreSQL queries that segment users into cohorts based on date logic, filter invalid survey events, and calculate aggregate satisfaction metrics.

    Data Manipulation (SQL/Python)Technical Screensqlpostgresqldata-aggregation
  • MetaMediumData Scientist
    Compute 7-day views and reactions by relationship

    This question evaluates skills in SQL-based data manipulation—specifically deduplication by longest duration, join-based attribution of reactions to views, window functions, distinct counts, aggregations, and date-range filtering within the Data Manipulation (SQL/Python) domain.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaMediumData Scientist
    Compute CTR overall and by campaign type

    This question evaluates data manipulation and analytics skills, specifically SQL aggregations, deduplication of event logs, time-window filtering, joins to campaign metadata, and safe ratio computation including division-by-zero handling.

    Data Manipulation (SQL/Python)Technical Screen
  • MetaHardData Scientist
    Compute High-Call Usage Rates

    This question evaluates a candidate's ability to perform advanced data manipulation and analytical SQL tasks, including joins, aggregations, timezone-aware date handling, rolling window metrics, distinct user counting, and counting user participations across roles.

    Data Manipulation (SQL/Python)Technical Screen