As someone in that field, I can assure you everyone is having to do a lot more CyberSecurity than they used to.

While there is a lot of AI slop out there, it’s also having a huge impact on the cyber security front, in that it's finding vulnerabilities that are many years old and also brand new ones, faster than ever before. This makes it harder for the good guys to keep up. It’s definitely important to be mindful of security these days.

you have to selfhost and encrypt everything :)

I actually have been using claude to go through all my old projects and review from a security perspective.

It flags a heap of things that I never considered, mainly because a lot of my projects were ad-hoc solutions to various issues that were written in a hurry and never intended to be visible to the general internet. But it also has been suggesting architectural and robustness changes that have some value, as a lot of stuff I wrote grew organically and weren't structured particularly well for future growth.

client side security

What do you mean by this? Like, MTLS or requiring people to install client certificates in their browsers, or installing certificates in some other client application. Or something else?

And who are/own the clients in question? These aren't B2C sort of customers, are they?