Why is node JS so hyped these days

Question

why every startup and every big company mention node JS is there programming language criteria

Answer 1

Long Answer
Node.js is an application runtime environment that allows you to write server-side applications built on Chrome's V8 JavaScript engine. It excels at the sort of scalable and real-time situations we are increasingly demanding of our servers.  It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, its ability to use JavaScript on both frontend and backend adds an advantage for development. Node.js package ecosystem, npm, is the largest ecosystem of open source libraries in the world that's why all companies adopted it.
There are two important things that makeNode.js development different to existing server-side frameworks is the use of JavaScript as a programming language and Asynchronous events.
JavaScript is the programming language that web applications are using on the client. Using the same language on the server-side means that the developer can apply his JavaScript knowledge both on the client and the server, and use the same functions as needed.
While most of the existing server-side frameworks use asynchronous architecture, Node.js uses an asynchronous architecture, which JavaScript can handle well. This means that the server reacts to events and sends events (messages) to e.g. the database. This style of programming is very different to a synchronous style and may be hard to use with other languages. Node.js employs an asynchronous style with asynchronous IO and can scale well.

Answer 2

NodeJs performance is high, best for high traffic websites.