I'm having the same issues as you. When I enquire how to apply I get directed to the Grandvalira website. Then I just get errors. Also, it will only appear in Spanish for me. When I change to the English page none of the information appears
Currently awaiting a reply specifically from the Pas de la Casa and Soldeu/El Tarter sites.
If I get any useful information for you I will reply here to you again.
Both soldeu.com and pasdelacasa.com are part of the booking agency Andorra Resorts. We are a booking agency so have no involvement with the recruitment of any Grandvalira staff, or their websites.
We have sent you both emails with information you may find useful,
Many thanks, Ian