I think this is kind of a given, today. I don't know many healthy, growing organizations for whom their "sysadmins" are not either originally developers or proficient in writing at least domain-specific code (I have always said that I am a software developer whose output is systems rather than web apps, because it's true; right now, with my current projects, I just wear both hats and get on with it!). Even the term "sysadmin" has largely disappeared in my neck of the woods; it has been largely replaced with "SRE" or similar, but that sort of position invariably seems to have development connotations.