I learned a new trick today on Spacemacs that is super ideal. I was watching a coworker use sublime text 2, and he used a shortcut to jump to the definition of a class. Spacemacs must have that too!

Spacemacs jump-to-definition

You have two options for jumping into a definition. To open in the same window:

, g g

To open in a new window:

, g G

or

g D

Note: To work in for ruby, you need to bundle install both pry and pry-doc.