Answer short: QA field is my primary expertise. I am just shifted to building tools and apps that are quality, testing, reporting and infrastructure oriented.
So CTO role was a greater shift, I had to learn hiring, managing a team, talking to vendors, all sorts of startup things.

Well, to answer the question, I choose projects that are interesting and challenging.

Being a CTO was that kind of o project. After that I was a lead developer building bridge service between docker and kuber interfaces for a huge CI infrastructure. And then joined Supabase, cause I like the product, supabase is looking for people with founder experience , and I am the first and single QA here. All my career journey is just a list of exciting challenges, and it was the one suitable for that path :)