Doesn't the iTunes and App Store backend still run on WebOjbects?

Yes, but while web objects was a first class thing in the objective c world back in 1995 the direction swung due Java from about 1997 onwards — I doubt there’s any non-Java WOA any more. For example, it was developed when 32 bit PowerPC was a thing and I don’t think it ever made it to 64 bit Intel.

How can you tell?

I worked there, and yes, most of the server side stuff is in Java and Go.

Disappointing but perhaps not surprising. Your experience is reasonably recent?

Do you need both or would just Go do :) ? Hate Java

If you were starting from scratch, you probably would start with a different system. However web objects was their web framework at the time which was ported from objective c to java decades ago and shifting legacy from any technology to another is practically impossible especially if that technology is a cost rather than a product.

I am not sure what is upsetting about the question was honestly wondering how realistic it is to work at Apple on services using primarily Go.

Either you ask someone who worked there, or you can trawl job postings.