Are there good careers as a code tester?

I started to code a few years ago but I've always been good to find flaws in my or my friends code, and how to fix them. I have a "why" way of understanding a situation instead of a "how", I'm not sure how to explain it clearly.

Basically, in my class, every time something breaks for my friends, I'm the one they ask for help. Once they tell me how their code works, I can visualize it and explain why it breaks. It comes naturally for me.

Are there jobs for that? Do high-end programmers test their code themselves or do they have someone do it for them? If it's a thing, how is the salary vs an actual programmer? I'll do some research but if anyone here is working on this field and could clarify for me I would appreciate it!

Thanks.