That would not apply to software developers, even if they call themselves engineers, software developers are not licensed professional engineers (i.e. civil engineers).

For example a Software Developer can't start a professional corporation in California like a lawyer, architect, civil engineer, accountant etc...

unless they have a college degree

a College degree != a professional license

The American National Society of Professional Engineers provides a model law and lobbies legislatures to adopt occupational licensing regulations. The model law requires:

1) a four-year degree from a university program accredited by the Engineering Accreditation Committee (EAC) of the Accreditation Board for Engineering and Technology (ABET),

2) an eight-hour examination on the fundamentals of engineering (FE) usually taken in the senior year of college,

3) four years of acceptable experience,

4) a second examination on principles and practice

5) written recommendations from other professional engineers.

Is a software engineer really a recognised proffesion in CA?

It's a proffesional level job, but reconisation usually means being a member of some sort of proffesional body - no idea what the software one of those would be?

I think they only have it in Texas as of now

Software "engineer" is not a (licensed) engineer, for the hundredth time.

It's a shame that doesn't exist. I've always thought you could make an especially strong argument for licensing for embedded software people, for many of the same reasons that a PE is licensed.

It wouldn't be a requirement for a job necessarily, but not a bad thing to have.

I doubt such a certification would have any correlation with ability. Maybe the platonic ideal of training and testing that you're thinking of, but not a certification written by the US government. Even competent parts of the government like NIST take forever to update their standards. It would be worse for a licensing bureau with practically no in-house software expertise.

You can get a computer engineering PE, which would probably be appropriate for the vast majority of embedded software developers. There was a software PE for a few years, but my understanding is that it was dropped for lack of interest.