It's been awhile, but I interviewed at LinkedIn some years ago and it sounded very much like an anything-goes ethic. It was based on feature ownership, so if you had an idea you could implement it however you wanted as long as you also supported it. I was left to think that flavor-of-the-week is very much a part of life there if a programmer wants it.
The age purge is ongoing even for long-established, mature code bases and projects, e.g. IBM, HCL, etc.