Javascript Promises in depth with V8 engine internals

JavaScript is often perceived as slow and not scalable due to its single-threaded nature. However, for I/O intensive tasks, JavaScript (particularly NodeJS) performs well by delegating I/O operations to the underlying OS threads and continuing with other tasks. The post explains the blocking and non-blocking nature of JavaScript, the role of C++ APIs, and how async programming works using callbacks, promises, and the event loop.