There's no point learning 10 new languages if what you can do with it doesnt go far for example from a normal CRUD application/Hello World application. Just set appropriate goals. In the end what you will be very good at is creating CRUD applications. Be objective in what you will be learning. For example, being a backend developer, you can learn new tech that further augment your skills.

For example use Ruby/Rails on the backend or a web app, learn Objective-c to create an app that gets data from that RoR app, and maybe use go to create an API for a section that is performance heavy, etc... So that everything builds up. You need to establish goals.