The industrial related meaning of a Mern Stack Developer is an software engineer who can work on various levels of an application stack. The term stack refers to the combination of components and tools that make up the application. The components could be in the front-end or the back-end of the system.
The main objective of Mern Stack engineer while working is to keep every part of the system running smoothly using Javascript as a sole backend and React as a frontend. A Mern Stack Developer can performs tasks ranging from resizing an image or text in a webpage to patching the kernel.