DAG Orchestration

Concepts covered: paDagOrchestration

What They Want to Hear 'A DAG (Directed Acyclic Graph) defines tasks and their dependencies. Airflow is the standard orchestrator. Each task is a node, edges define ordering. If Task B depends on Task A, Airflow will not start B until A succeeds.' Then the key insight: 'Cron can schedule a job, but it cannot manage dependencies between jobs, retry failed tasks, or show you the state of your entire pipeline at a glance. That is why Airflow exists.'

About This Interactive Section

This section is part of the Making It Repeatable: 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.