Interactive Spark learning

Learn Spark & Databricks by seeing what happens under the hood.

From your first DataFrame to Catalyst, shuffle, AQE, Delta Lake and production architecture — explained through a simulator you can step through.

No account needed. Your progress is saved automatically.

What you will actually see

Educational simulation · not live cluster data

Now showing: Driver

How it works

Visualization first, text second — so the mental model comes before the jargon.

Step 1
Watch it execute
Step through Driver → Job → Stages → Tasks → Shuffle at your own pace. Every step says what Spark is doing and why.
Step 2
Inspect any piece
Tap a task to see its partition, executor, and host. The three ideas people most often confuse, kept clearly separate.
Step 3
Then go deeper
Switch to Learn or Interview when you want internals, production failure cases, and the questions you will be asked.

See why one partition means one task, and how executors pick that work up.

Watch records fly across the cluster so each key lands on one reducer.

Flagship lesson

groupBy + show() — 11 guided steps, from your code to the result.

23 lessons · 5 simulators · interview tracks