You really need an EE or CompSci degree these days. That's the first point of call.
I don't have either but it was a little different when I started. I managed to build a reputation up on the side and go from there. Eventually people stop asking about qualifications.
EE is probably more important than a comp sci education for embedded work. Its a fairly complicated field which deals with things far below the abstraction of a machine.
If anyone mentions the word Arduino though, stop listening there and find someone else. They're assumed to be like the real world but are faaaar from it.