> In order to fire a German employee outside of their multiple month trial period they have to commit a crime or willfully ignore instructions, or the company must be in financial trouble due to outside circumstances. Underperforming is not a legal reason to fire somebody.

Do you have a source for this claim? I'm not an expert in German employment law but would love to learn more.

A quick Google produces this: https://boundlesshq.com/guides/germany/end-of-employment/

The only thing that seems different from Ireland (where I live) is the Works Council hearing part.