I work at a small hedge fund in London, started on £28k (actually might have been less, I literally can't remember now), after 4 years I am up to £40k, with around £5k bonus each year.
I have basically been doing CRUD of various flavours the whole time under a bullying atmosphere, utterly soul-destroying and it's got me stuck in the Stockholm syndrome scenario, my skills ground down to the point where I literally can't get another job to get out of it. Am working very hard to counter it, but it's a big job, probably another year of work to stand a chance of getting a decent software job (I'm not going to try for another internal finance job, if that sucks as much it'll be pretty impossible to bear).
So yeah, I don't recommend it, though it might just me having bad luck here.
I think very few internal jobs, finance included, are even vaguely bearable for hackers - I heard the idea that finance likes to hire overqualified people for monotonous/trivial jobs to make sure they're done right, so you have to be really careful.
[1]:http://www.chadfowler.com/2010/12/30/dead-end-jobs-are-you-s...
If you would, drop me an e-mail (see profile). My employer is hiring. Located near Moorgate. Not a deathmarch.
Edit: Hmm.. I think HN hides e-mail addresses. http://bhickey.net/contact
With 4 years experience at an investment bank you could be making quite a bit more than that, at a hedge fund you should be getting a risk premium on top of that as well.
There are various tech roles in hedge funds and in finance, and it sounds like the @throwaway___ is in a role that is considered "IT" rather than part of a quant/trading desk, which translates to no real bonus, and to not being considered a source of revenue.
This isn't Silicon Valley. Rightly or wrongly, they just want someone to come in at 9am, work through their assigned bugs and feature requests, get a sandwich at Pret A Manger at 1pm, work through some tickets and go home at 5pm. Nobody's interested in hiring "hackers", experimenting with funky languages, or doing anything remotely unpredictable. If you're on a trading desk it's a different story, but it's definitely possible to work at a hedge fund or an investment bank and get a shit deal.
Edit: Basically, it's your responsibility to maintain your skill set, by any means necessary. Your employers aren't paying you to be a well rounded developer, even if you think they should be.
I have been working on my skill set, I know C# pretty damn well, I have taught myself aspects of software engineering + computer science I didn't have, etc. etc. - it's just that there are gaps, lots of gaps and more than that, a complete lack of confidence. This stuff grinds you down so much that it becomes very hard to resurface, that's part of the problem.
I am working hard on filling those gaps, but I think it'll probably take a year before I've sorted it. I went for a bunch of interviews at other finance places recently and the gaps were exposed very clearly there, so this is based on evidence.
Anyway, I don't want to talk much more about this unless stuff starts becoming toooo identifiable.
Just grit my teeth time really, but it's hard.
You're correct, £25k seems to be a ballpark figure for software houses. Looking at it statistically, average salary for Imperial graduates is something like £35k, so you can do the math and infer what the top grads are earning.
Not sure what a starting salary would be, but I would bet it would be > 30k. After 5 years you would probably be on > 60k, but if you're quite specialist (in terms of finance based skills) you could be earning much more.