Spend your time coding. If you have free time, improve your craft. Find something to write that you find interesting. You'll get better at your core skills,

Spend your time coding. If you have free time, improve your craft. Find something to write that you find interesting. You'll get better at your core skills, and quite likely you'll find one or other open source project that you use in your code that needs improvement. If you do, that's going to be your worthy cause. It's something you'll find interesting and relevant, and you will definitely feel like you contributed.