Many Spanish young developer do this because salaries are substantially higher in UK, and an experience in an English speaking country is highly valued by comp

Many Spanish young developer do this because salaries are substantially higher in UK, and an experience in an English speaking country is highly valued by companies in Spain (if they ever plan to come back), and of course for the experience itself. I have at least three ex coworkers that moved to UK for these reasons, even if at the time they were (more or less) happily employed in Spain.