Playground

Simulators you can step through

Educational simulations — not a live cluster. Click Play, then inspect.

• beginner

  Spark Execution Simulator

  Full job → stage → task → shuffle walkthrough.

• intermediate

  Shuffle Simulator

  Watch keys hash to reducers.

• intermediate

  Join Simulator

  Broadcast vs shuffle join, side by side.

• senior

  Data Skew Simulator

  One fat partition vs a salted plan.

• advanced

  AQE Simulator

  Runtime coalescing and skew handling.