This is not directly the question you're asking, but I find that salary info on London isn't very accurate on Hacker News. London has always been a contract-heavy market, and the best money was had while contracting. Since IR35 this may have changed somewhat, but I've mostly found that rates on contracts inside IR35 have gone up to compensate.
I lead the development of a product in an investment bank, and I concentrate almost entirely on frontend web dev. I've been on a contract for 5 years, and currently pull in £900 per day outside IR35 (£200k equiv or $260k). We routinely hire devs for £700-750 per day and we STILL find it difficult to hire.
I can walk into a number of roles tomorrow paying at least £800 per day.
I lead the development of a product in an investment bank, and I concentrate almost entirely on frontend web dev. I've been on a contract for 5 years, and currently pull in £900 per day outside IR35 (£200k equiv or $260k). We routinely hire devs for £700-750 per day and we STILL find it difficult to hire.
I can walk into a number of roles tomorrow paying at least £800 per day.