Katkat

practice a little every day, paws crossed ♡

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 121–129 of 129 results

  • 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
  • XPengMediumData Engineer
    Build a Least-Recently-Used Store

    This question evaluates understanding of caching and eviction policies and practical proficiency with data structures such as hash tables and ordered collections for tracking and updating recency.

    Coding & AlgorithmsTechnical Screen
  • ZooxMediumData Engineer
    Design Transaction Data Quality Checks

    This question evaluates the ability to design and implement data quality checks for relational transaction and vendor datasets, focusing on integrity constraints, referential integrity, business-rule validation (refund logic), missing/invalid values, and anomaly detection.

    Software Engineering FundamentalsTechnical Screen
  • ZooxMediumData Engineer
    Design teleoperations data models and pipelines

    This question evaluates competency in data modeling, real-time and batch pipeline architecture, telemetry ingestion, metrics design, and operational monitoring for teleoperations and autonomous vehicle stability.

    System DesignOnsite
  • ZooxMediumData Engineer
    Explain seasons and compound interest

    This question evaluates quantitative reasoning and basic scientific literacy by testing understanding of Earth's axial tilt and seasonal temperature variation alongside exponential growth and compound interest calculations.

    Software Engineering FundamentalsOnsite
  • ZooxMediumData Engineer
    Write SQL revenue and anomaly queries

    This question evaluates SQL proficiency and data engineering competency in revenue aggregation, netting purchases and refunds, joining transaction and vendor tables, and designing data quality and anomaly detection checks.

    Coding & AlgorithmsOnsite
  • ZooxMediumData Engineer
    Write Transaction Analytics SQL Queries

    This question evaluates proficiency in SQL for analytical queries, covering aggregation, time-based filtering, joins between transactions and vendor metadata, and the use of ranking/window functions for top-N calculations.

    Coding & AlgorithmsTechnical Screen
  • xAIMediumData Engineer
    Build a One-Pass Data Cleaning Pipeline

    This problem tests your ability to design a memory-efficient, scalable data streaming pipeline that processes raw web-scraped documents into a high-quality dataset for model pretraining.

    System DesignTechnical ScreenData EngineeringStreamingData Cleaning
  • xAIMediumData Engineer
    Implement two string utility functions

    This question evaluates proficiency in string manipulation and text processing, including character counting, tokenization by spaces, case-sensitive comparisons, and preserving original word order.

    Coding & AlgorithmsTechnical Screen