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Data Engineer 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 1–16 of 16 results

AgodaEasyData Engineer
Find the Longest Calendar-Day Streak with All Employees Present
Identify dates when every employee is present and compute the longest consecutive streak, treating missing attendance as a gap.
Data Manipulation (SQL/Python)Technical Screen
AgodaEasyData Engineer
Rank Customers by Monthly Revenue with Competition Ties
Aggregate customer revenue by month and return top competition ranks, preserving tied totals and deterministic display order.
Data Manipulation (SQL/Python)Technical Screen
AgodaEasyData Engineer
Return Every Employee with a Mapped or Default Unique ID
Join employees to unique-ID mappings while preserving unmatched employees and applying an explicit fallback identifier.
Data Manipulation (SQL/Python)Technical Screen
BloombergMediumData Engineer
Write PostgreSQL string-manipulation query
This question evaluates proficiency in PostgreSQL string manipulation, regular expressions, URL parsing, key-value parsing and timestamp-based filtering for data transformation tasks.
Data Manipulation (SQL/Python)Technical Screen
ClickhouseMediumData Engineer
Answer SQL And Data Warehouse Fundamentals For A Data Engineering Interview
This problem tests foundational knowledge of SQL set operations, performance optimization techniques for join operations, and the architectural principles behind building scalable data warehouses.
Data Manipulation (SQL/Python)Technical ScreenSQLData WarehousingWindow Functions
MetaMediumData Engineer
Compute reservation diff for largest member
This question evaluates competency in relational data manipulation and aggregation using SQL or Python, including joins, grouping, and handling missing referrer relationships.
Data Manipulation (SQL/Python)Technical Screen
MetaMediumData Engineer
Return count and renewal percentage of unreturned good copies
This question evaluates proficiency in SQL data manipulation, including conditional filtering, NULL handling, aggregation, and computing conditional percentages across related tables.
Data Manipulation (SQL/Python)Technical Screen
MetaMediumData Engineer
Solve Python and SQL data tasks
This question evaluates data manipulation and engineering competencies by testing Python proficiency with nested data structure handling, complexity analysis and test-case design, alongside SQL proficiency in UTC-aware aggregation and per-user deduplication to compute daily active users; it is categorized as Data Manipulation (SQL/Python) within the data engineering domain. Such problems are commonly asked to assess practical implementation ability and robustness under edge cases, as well as conceptual understanding of time/space complexity and correct date-time handling, reflecting a primarily practical application with elements of conceptual analysis.
Data Manipulation (SQL/Python)Technical Screen
MetaMediumData Engineer
Write SQL for library analytics
This question evaluates proficiency in SQL-based data manipulation and analytical querying, focusing on relational schema navigation, joins, aggregation, filtering, and handling temporal and conditional metrics within a library dataset.
Data Manipulation (SQL/Python)Technical Screen
NuroEasyData Engineer
Compute unique duration by merging intervals
This question evaluates a data engineer's proficiency in temporal data manipulation and interval-set reasoning using SQL and Python, specifically skills in merging overlapping intervals and computing deduplicated cumulative durations.
Data Manipulation (SQL/Python)Technical Screen
Otter.AiMediumData Engineer
Find Every Project with the Most Employees
Build a PostgreSQL aggregation that returns every project tied for the largest employee count. This compact exercise checks grouping, maximum selection, tie preservation, empty-input behavior, and careful use of primary-key guarantees.
Data Manipulation (SQL/Python)Technical Screen
Otter.AiMediumData Engineer
Find the Highest-Paid Employee in Each Department
Work through a tie-aware PostgreSQL problem that finds every highest-paid employee in each department. It assesses relational reasoning, correct joins, duplicate-name handling, and precise output semantics without assuming a single winner.
Data Manipulation (SQL/Python)Technical Screen
RbcroyalbankEasyData Engineer
Explain pandas and SQL basics
This question evaluates familiarity with pandas data structures (Series vs DataFrame), SQL filtering semantics (WHERE vs HAVING), and practical SQL aggregation for detecting duplicate records, assessing competencies in data manipulation, aggregation, and basic data quality checks.
Data Manipulation (SQL/Python)Technical Screen
TikTokMediumData Engineer
Debug a Hive Query for DAU
This question evaluates proficiency in Hive/SQL query formulation, data partitioning and pruning, join and aggregation semantics, timestamp handling, and performance tuning for large-scale analytics.
Data Manipulation (SQL/Python)Technical Screen
TikTokMediumData Engineer
Debug a Hive insert query
This question evaluates a candidate's ability to debug Hive INSERT/SELECT operations, focusing on schema and column alignment, data types and casts, partition handling, file formats/SerDe, ACID/transactional constraints, and syntax or reserved keyword issues.
Data Manipulation (SQL/Python)Technical Screen
TikTokMediumData Engineer
Explain a SQL query result
This question evaluates proficiency in SQL result-set interpretation and reasoning about joins, filters, aggregations, window functions, NULL handling, duplicate rows, and ordering within the Data Manipulation (SQL/Python) domain for a Data Engineer role.
Data Manipulation (SQL/Python)Technical Screen