You might have used redux with react, as it is a widespread practice. Many people use redux-saga or redux-thunk for async actions as middlewares. Redux allows you to create your custom middleware as per your requirement. A middleware can be added in between dispatch and reducers so that we can alter the actions or can dispatch other actions (for async actions).

This is done with a function returning function. So, let’s first understand about function returning function.

It is simple and can be done as follows -

A service worker is a script that runs in the background and does not require the web page to load. It runs on a separate thread and cannot directly access the DOM. It interacts with webpages through the post messages.

For the first time, I used service workers to push notification, and it is effortless to integrate it, in your javascript code.

The service worker is asynchronous and cannot use XHR and localStorage inside it.

As of this writing, Concurrent mode is experimental. It allows the rendering process interruptible. It doesn’t block the browser from making changes to the DOM and continues rendering in memory.

The performance of an Application can be good or bad depending on the quality of code. In React, The Profiler API helps in measuring the performance of a component and enhancing it.

The Profiler API for DevTools first got shipped in the 16.5 React version. It helps developers find difficulties in your web application. In 16.9 version, the React team has gone a step further to enhance the API.