Ask HN: What companies in London should one apply for an internship at?

I'm looking for an internship for the next summer. I know how to use Google (or DDG in my case) but I thought asking here wouldn't hurt since I'm sure lots of HN users have experience with past internships in London. Any info at all is highly appreciated!

I was hoping Mozilla had an open place in Europe (ideally London) but it doesn't seem to be the case.

So, where should I apply?

Thanks in advance.