It's much harder than it used to be. EU citizens now need a visa to stay and work for longer than a few months, and they mostly need to obtain a Skilled Worker Visa which has occupation and salary requirements.
Since Brexit I've noticed that my London-based employer has had an uptick in hiring Indian and Pakistani nationals, especially in Dev and QA. It's probably not the outcome that most Brexit supporters were gunning for, although I did hear that a large proportion of South Asians did in fact vote to leave for this reason.
Is this part still true though?