Do I have to be in Software Engineering/Computer Science to FatFIRE?

Going to Australia in 2 years , currently I'm a college student but the idea of FatFIRE really appeals to me. Is it possible to achieve it through a salaried job in core branches or would I have to start my own company/work in software engineering to achieve this. I've seen alot of the posts of people with big corpuses and they usually seem to be in US doing software engineering or owning their own buisness.

Would love to hear inputs from people who have wisdom that comes with age.