[Alekhine]

What editor are you using to do this? I assume it's vim or emacs.

[globular-toast]

I have this with yasnippet in emacs. It's more than just simple expansion too. It expands to a skeleton to fill in the blanks, so f expands to a function definition and then allows you to put in parameters, return type, then body or whatever makes sense in the current language.

[RheingoldRiver]

I don't do anything remotely this elaborate, for me it's a couple phrases to bring up the URLs of public discord servers I have to link to frequently. But for this, I use Autohotkey in Windows. It works really well.

[codedokode]

Sublime Text allows to add arbitrary abbreviations, but I assume almost any code editor supports it.