File Ingestion

Concepts covered: paFileIngestion

What They Want to Hear 'Files are the most common ingestion method. A vendor drops a CSV on S3, an event notification triggers the pipeline, and we validate before ingesting.' That is the baseline answer. Then show depth by naming formats and their tradeoffs: CSV is universal but slow at scale. Parquet is columnar, compressed, and 10-30x faster for analytics. JSON is flexible but verbose. Format Cheat Sheet

About This Interactive Section

This section is part of the How Data Moves: Beginner lesson on DataDriven, a free data engineering interview prep platform. Each section includes explanations, worked examples, and hands-on code challenges that execute in real time. SQL queries run against a live PostgreSQL database. Python runs in a sandboxed Docker container. Data modeling problems validate against interactive schema canvases. All content is framed around what data engineering interviewers actually test at companies like Meta, Google, Amazon, Netflix, Stripe, and Databricks.

How DataDriven Lessons Work

DataDriven combines four interview rounds (SQL, Python, Data Modeling, Pipeline Architecture) with adaptive difficulty and spaced repetition. Easy problems get harder as you improve. Weak concepts resurface until you master them. Your readiness score tracks progress across every topic interviewers test. Every lesson section ends with problems you solve by writing and running real code, not by picking multiple-choice answers.