> +1 if you suggest something cutting edge that very less people know about!
Well I would suggest learning about The Fuchsia Operating System (a new OS by Google) which is extremely cutting edge of OS Development and its kernel (Zircon) brings interesting concepts to the table in terms of design and implementation. It is bleeding edge enough that Flutter is used for the new apps, Rust is used for the drivers and the netstack uses Go and a official port is already on the way to upstream.
All the Flutter apps, you're making will run instantly on Fuchsia, and in this decade, I would place a bet on Fuchsia to be the successor of both ChromeOS and Android.