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Coding questions
Explore algorithm tutorials, coding and system design questions, interview experiences, and computer science study guides.
1,899 resources · Page 1 of 80
Coding questions · Waymo
2D Max Pooling That Also Returns the Coordinates of Each Window Maximum
Implement 2D max pooling with a k-by-k window and a stride, and for each window also return the row and column of its maximum, breaking ties by smallest row then column. Tests window indexing without padding, output sizing, and argmax bookkeeping.
Coding questions · Amazon
Add One Source to Minimize Grid Inconvenience
Minimize the worst inconvenience in a binary grid by adding one colored source. Movement is allowed in eight directions, and the solution must handle grids that begin with no source at all.
Coding questions · Amazon
Add, Remove, and Find Values in a Bounded Integer Universe
Implement constant-time bounded-integer set operations with direct addressing, explicit duplicate semantics, initialization cost, and sparse-universe tradeoffs.
Coding questions · Additive Ai
Advance Game of Life with Reduced Auxiliary Storage
Advance Game of Life by one generation while preserving simultaneous updates, handling grid boundaries, and reducing storage in an in-place implementation.
Coding questions · Netflix
Aggregate D1 retention cohorts in SQL
This question evaluates a candidate's competency in time-series cohort analysis and SQL-based data manipulation, specifically measuring DAU, new-user cohorts, D1 retention and revenue-per-user while handling deduplication and user filtering.
Coding questions · Capital One
Aggregate exam scores with NULL handling
This question evaluates proficiency in SQL data manipulation, specifically joins (including LEFT JOIN behavior), NULL handling with ISNULL/COALESCE, conditional aggregation, distinct counts, and date-based filtering within the Data Manipulation (SQL/Python) domain, focusing on practical application of query-writing skills.
Coding questions · Rippling
Aggregate expenses by person, trip, and category
This question evaluates a candidate's ability to perform efficient data aggregation, use associative data structures (maps/dictionaries), and reason about time and space complexity when processing large collections of records.
Coding questions · Meta
Aggregate Netflix metrics in SQL
This question evaluates a candidate's proficiency in SQL data aggregation and construction of cumulative metrics for streaming analytics, including handling alignment of records when identifiers may appear in only one dataset.
Coding questions · CVS Health
Aggregate radiology spend and derive fiscal month
This question evaluates a candidate's competency in data manipulation and preprocessing using SQL/Python, covering robust dtype specification, null handling, numeric aggregation and percentage computation, datetime parsing, and fiscal-month derivation.
Coding questions · Mixpanel
Aggregate User Events and Check Join Uniqueness
Aggregate user events and retain all users in PostgreSQL, computing event count, distinct active dates, earliest event, and join uniqueness.
Coding questions · Robinhood
Aggregate user logs into 30-minute sessions
This question evaluates data engineering competencies in time-series sessionization, datetime parsing and arithmetic, grouping and aggregation, distinct-count computation, and CSV log processing.
Coding questions · Pinterest
Aggregate video time and unique pins in Python
This question evaluates competency in data aggregation, deduplication, and algorithmic efficiency by requiring computation of category-level averages with tie-breaking and per-user unique counts, demonstrating proficiency in Python and SQL-style data manipulation.
Coding questions · Instacart
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.
Coding questions · Harvey
Allocate Unique File Names in an In-Memory Vault
Allocate unique vault file names with the smallest available numeric suffix, handling preexisting suffixes, repeated requests, and case sensitivity.
Coding questions · Chime
Analyze Acquisition Channels for User Value and Retention
This question evaluates proficiency in SQL/Python data manipulation and analytics, testing aggregation, cohort and retention analysis, ranking, joins and window-function usage along with interpretation of user-level revenue metrics.
Coding questions · Meta
Analyze Ad CTR and Convert Transactions to USD
This question evaluates proficiency in calculating and ranking per-user ad click-through rates and normalizing transaction amounts across currencies, testing competencies in aggregation, ranking logic, temporal joins, and currency conversion.
Coding questions · TikTok
Analyze and Clean European Ecommerce Sales Data
This question evaluates proficiency in data manipulation and analysis with Pandas, covering time-window filtering, regional subsetting, deduplication, missing-value handling, aggregation, and visual summarization.
Coding questions · Meta
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.
Coding questions · Meta
Analyze Conversation Engagement and Reaction Usage Effectively
This question evaluates data manipulation and analytical skills in SQL and Python, focusing on deduplication of unordered sender-receiver pairs, temporal aggregation and differences, computation of counts and percentages, and the design of query-friendly engagement metrics.
Coding questions · Meta
Analyze Cross-Country Call Data for Recent Trends
This question evaluates a candidate's competency in relational data manipulation, including joining tables, aggregations, time-based filtering, and duration calculations using SQL or equivalent Python tools.
Coding questions · DoorDash
Analyze Customer Purchase Patterns Using SQL Query
This question evaluates a candidate's competence with SQL data manipulation and windowing concepts, specifically using ordering and partitioning to compare and rank events within a customer's purchase history.
Coding questions · Notion
Analyze document collaboration from CSV logs
This question evaluates data manipulation and analytical competencies—particularly deduplication, joins, aggregation, co-occurrence counting, and metric definition—applied to CSV access logs and user metadata.
Coding questions · DoorDash
Analyze Driver Requests for Food Delivery Orders
This question evaluates data manipulation and analytical SQL skills in the Data Manipulation (SQL/Python) domain, focusing on window functions for ranking and temporal comparison, joins, and aggregation when analyzing orders and driver requests.
Coding questions · Pinterest
Analyze Global Engagement and Impressions with SQL Queries
This question evaluates proficiency in SQL-based data manipulation and analytical querying, covering aggregation, grouping, ranking, and the correlation of impressions with user engagement and feature usage metrics.