Async (Asynchronous)
Asynchronous programming lets operations run independently of the main program flow. Instead of waiting for a task to finish before moving on, async code starts the operation and continues with other work, handling the result once it becomes available.
Why Async Matters
In traditional synchronous programming, each operation blocks until completion. For I/O-bound work like network requests, database queries, or file operations, your application spends most of its time idle.
Asynchronous programming solves this by allowing your code to:
- Start a task and immediately move on to other work
- Handle the result via callbacks, promises, or async/await when it’s ready
- Process multiple tasks concurrently without threading complexity
Async in JavaScript/TypeScript
// Synchronous — blocks until the response arrives
const response = fetchSync('/api/data');
const data = parseSync(response);
// Asynchronous — non-blocking
const response = await fetch('/api/data');
const data = await response.json();Async and Task Queues
Task queues like AsyncQueue push asynchronous processing even further. Instead of waiting for a long-running operation inside your application process, you offload the work entirely:
- Your application sends a task to the queue (milliseconds)
- A worker picks up and processes the task (minutes to hours)
- The result is stored and available via API
This pattern is essential for serverless architectures with strict execution time limits and per-millisecond billing.