Playground

Interactive Simulations

Reading about how something works is one thing. Watching it happen is another. Each simulation is an interactive 3D playground paired with a deep-dive article.

JavaScriptRuntimeAsync

The JavaScript Event Loop

3D runtime stage

Watch the call stack, Web APIs, microtask and macrotask queues come alive on an orbiting 3D stage. Step through Promise vs setTimeout and microtask-chain scenarios one event at a time and see exactly why the console prints in the order it does.

  • Drag to orbit
  • Scroll / pinch to zoom
  • Step through events
  • Play full run
  • Adjustable speed

More simulations are on the way — each new deep-dive article ships with one.