I met one of the founders/owners of mullvad at CCC in Germany over 8 years ago. I gotta say, I've never met someone so happy to talk about how unbelievably paranoid they are about security and how much effort went into not only protecting the VPN endpoints themselves but the team's devices so they can't be used as a point of compromise. Wasn't a sales pitch, just a multi hour long discussion around privacy and tech that enables it.

I learnt a lot from that dude and have been using mullvad for years since since it's the only VPN provider I've ever personally met. Oh yeah, decent speeds etc as well :P