Asynchronous JS: Event Loop, Microtasks & Coroutines
Demystify asynchronous execution: the event loop, microtask queues, Promise resolution mechanics, async/await coroutines, and resilient networking with AbortController.
Comfortable with synchronous functions, callbacks, and object delegation.
Master the single-threaded event loop, Promise combinators, async/await coroutines, and the Fetch API with AbortController.
Read in order, or jump to what you need.
Every lesson builds on the one before it. Open any lesson to read the explanation, run the examples, and try the practice challenges.
- 07.01The Event Loop, Microtask Queue & Execution Phases4 min
Step inside the asynchronous heartbeat of JavaScript. Trace execution order across the Call Stack, Microtask Queue, and Task Queue (Macrotasks).
- 07.02Promise Architecture: State Transitions, Chaining & Combinator Mechanics4 min
Deconstruct the Promise specification. Master pending/fulfilled/rejected state transitions, .then chaining, error propagation, and all 4 combinators.
- 07.03Async/Await: Generator Coroutines, Error Handling & Sequential vs Concurrent Traps4 min
Master modern async/await syntax. Understand coroutines under the hood, synchronous-looking try/catch error boundaries, and avoid sequential blocking loops.
- 07.04Modern Networking: Fetch API, Response Streaming & AbortController Timeouts4 min
Master modern HTTP networking in JavaScript. Understand Fetch status codes, stream consumption, request cancellation, and timeout management using AbortController.
Ready to move on?
Construct an asynchronous pipeline resilient to network latency, retries, and timeouts.
Open the module self-check