Mirosław Stasiak

Promises are used to manage asynchronous operations, which were eventually added to JavaScript in the ECMAScript 2015 specification. Promises simplify the previous approach to async actions control, based on the callback function. I hope this text will clarify the subject to you, as I’m going to give you a detailed description of what Promises are and how to make good use of them.

One of the greatest strengths of the React library is its performance level. This technology is actually as quick as a flash. Such a state of affairs can easily change, though, and just a few bugs can significantly slow down the functioning of a created application. That’s why I’d like to discuss a couple of popular and effective tools to diagnose performance problems.