Express.js, a marvelous framework for Node.js
Node.js is famous for its role as a full-stack JavaScript for serving both the client and the server-side applications. It has a variety of frameworks for supporting its role. Express.js is the most popular Node.js framework with more than 43,000 GitHub stars.
Express.js
Express.js is the number one node.js framework that is favored by most developers. By the end of 2019, it will reach the incredible mark of 2 million daily downloads. So what are all the things we love about Express.js?
Some of the top features of this framework are:
Simplicity
Express.js is simple to configure and customize. It is also easy to integrate with different template engines such as Jade, Vash, EJS, etc.
In combination with Node.js, Express.js can be utilized to build APIs for single-page, multi-page as well as various mobile and web applications.

Extensibility with middleware
A middleware is a chunk of code that has access to a user’s request, the application’s response, and the next middleware to be used.
Express.js includes many middleware modules which help users to better respond to HTTP requests. With the help from middleware, developers are also able to add, remove, or modify various features to and from the application, giving high scalability to the application.

Performance
Templating
Express.js comes with an impressive view system which supports more than 14 template engines.
Express.js’s templating engine allows web pages to have dynamic content by constructing HTML templates on the server side, changing dynamic content with their proper values, and then sending these to the client side for rendering.
Routing
Routing helps web applications to conserve web page states through their URLs. These URLs can be shared with other users, and visiting these URLs will take users to the exact page state that was originally shared.
Express.js has an even more advanced routing mechanism than Node.js. It supports robust routing. It allows users to define routes of your application based on HTTP methods and URLs. Express.js’routing can handle highly dynamic URLs.
Debugging
Express uses the debug module internally to log information about route matches, middleware functions that are in use, application mode, and the flow of the request-response cycle (expressjs.com).
This mechanism allows developers to quickly identify the source of bugs and correct them as soon as possible.
Support from big community
Express.js easy to learn, well-documented with a large and supportive open-source community.