I would assume it's the same amount of effort as before, if you're coming from outside the EU.
I can attest to the UK having well-paid developer jobs though, especially in London. I'm not in London but I have friends who are and they're doing well.
I would go even further and say it's easier now for non-EU people, because we just eliminated a whole class of advantaged competition. Now when you compete with someone from the EU you're on equal terms.
Everyone always talks about London, but misses out some of the other cities/large towns.
Manchester maybe a better option than London. Manchester is cheaper and has almost all the things you want from London without a lot of the negatives. Pay isn't nearly as good but the costs of living in Manchester are about 1/2 to 1/3rd of what London is.
If you want better weather the south-coast has Bournemouth (lots of smaller to mid-sized companies that do web development and insurance).
I moved from London to Manchester and my experience wasn't positive. While it might be cheaper there wasn't a lot of jobs. You are better off sticking to the South East.
yeah I'm based near Leeds and I've had a great career working across Yorkshire. I just reference London for the international audience, and because it's got that kind of urban metropolitan environment that most developers seem to prefer (even though it's not my cup of tea).
We're not known for the good weather up here, but thankfully it's spring this week so it's nicer.
Yes, developers jobs are well paid in London, depending on the company, there are several places that take advantage of their developers and pay poorly.
My advice to most London devs is move company often until you find a salary you're happy with, companies need you more than you need the company.
I can attest to the UK having well-paid developer jobs though, especially in London. I'm not in London but I have friends who are and they're doing well.