What's the tech scene in London like?

I relocated to London a few months back, in the middle of the lockdown. I've spent the last decade or so in India, mainly Bangalore, which ofcourse has an incredible tech scene. Was hoping to learn from the UK community here what to expect in London.

From the little that I saw, there's not a lot of big tech as such (as far as engg / product) is concerned, did see quite a bit of SaaS/consumer and fintech.

Would love to learn more about the tech scene/community here. Places to go to, forums to check out, stuff like that.