Work visa (cuenta ajena): your Spanish employer files the residence-and-work authorization for you (form EX-03) before you move — this route can't be self-filed, so secure the job offer first and coordinate timing with the employer's filing

This is the route most people picture when they say "work visa" — and its defining feature surprises everyone: you don't file it, your employer does. The Spanish company applies for your residence-and-work authorization (the EX-03 in the title) while you're still abroad, and only after it's approved do you lodge the visa at your consulate. Practically, that means the job hunt IS the visa process: until an employer commits to filing, there is nothing for you to submit.