I actually sat down to really learn what SOLID meant a few years ago when I was getting a new contract and it came up in a few job descriptions. Must have some deep wisdom if everyone wants SOLID code, right?

At least two parts of the SOLID acronym are basically anachronisms, nonsense in modern coding (O + L). And I is basically handled for you with DI frameworks. D doesn't mean what most people think it does.

S is the only bit left and it's pretty much open to interpretation.

I don't really see them as anything meaningful, these days it's basically just make your classes have a single responsibility. It's on a level of KISS, but less general.