More often than not recruiters (external and in-house) make up large numbers to get you to reply. Here is a verbatim quote from a mail I got last year:
> For the right candidate year 1 comp will be up to £500k.
After going through a three hour coding test, phone screen + onsite it turned out to be 120k + smallish bonus. Maybe I'm not the right candidate but most likely 500k was never on the table.
It's not the first time this has happened to me or people I know either. What I'm getting at is that I'd take the Oxford Knight compensation numbers with a pinch of salt. Those 300k jobs _do_ exist but nowhere near as many as in the US.
Additionally levels.fyi or glassdoor data doesn't support a large number of 300k jobs in London.
I often see cash compensation >300k on there.
Here's one for precisely 150k right now https://oxfordknight.co.uk/jobs/big-data-engineer/.
These aren’t junior jobs, and they often require you to be in central London so your money won’t go as far, but these jobs do exist.