I’m currently working on the Front-End Libraries certification and I was wondering if it is fine to use some side libraries like Material-UI to set up some additional styling for my components in the projects? For example, while creating a Drum Machine I decided to add switch buttons, should I be setting them up from the scratch with doing CSS/Sass on my own or could I use Switch component from the Material-UI for such additional feature?
It is fine for you to use libraries, and tools outside of the curriculum. The main idea of the projects is for you to practice the ones used in the curriculum, but one of the main purposes of the curriculum is to give students a path to learn web development, along with programming, and we encourage you to learn much more outside of these platforms. freeCodeCamp cannot teach you everything.