[nickmccann]

I found this quick read describing domain fronting interesting: http://blog.attackzero.net/2015/11/domain-fronting-and-you.h...

[NoGravitas]

This article on [domain fronting][0] is very informative, though also quite long.

[0]: https://www.bamsoftware.com/papers/fronting/

[duskwuff]

Surely the real domain name of the service will appear in the server certificate?

[temprature]

The server returns the certificate of the name given in the SNI, which is the fronted domain, not the real one.