Given Brexit, over the next few years, in London:
1. What will happen to DEMAND and SUPPLY for dev roles?
2. What will happen to the CONTRACT and PERM markets for dev roles?
My opinion: investment dearth will lead to decreased DEMAND overall and slow CONTRACT market, as business focuses on core and prunes more speculative investment. PERM / CONTRACT ratio increases as cut to commercial property prices and labour costs tempts foreign companies to set up ops in UK. Foreign pros in UK leave for a better deal elsewhere, net migration decreases for similar reasons (~20% cut to GBPUSD, 1% inflation...).
From the recruiters I talked to recently, it had no effect. From the interviews I had recently, it had no effect. Still recruiting and expanding.
One of my past company recently interviewed with journalists to announce that they are extending their operations and opening a new office in the USA. The next day the news published an article "<company> is leaving the UK after the Brexit". I'll let you imagine the surprise when we discovered the article the next morning. That's just 100% wrong and misleading.
I'm now willing to extrapolate that 90% of brexit announcements are fake invented by journalists for sensationalism. Nothing is happening, really.
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Regarding the GBP exchange rate.
As in all the major cities in the world, most of the income goes to pay the rent. The rent is in local currency, unaffected by USD-EUR-GBP rate.
We might hit a +10% on food price (and gaz) in a near future. It might get harsh[er] for big families and low income jobs, it's fine for people with good salaries. (Not to mention free catered lunches at tech jobs :D)