About doing one thing and doing it well, the best (anti) example is systemd. I think that having a DNS resolver and mounting your partitions should be two totally separated things. Fortunately nobody uses syste... Oh, wait!
About the code should be understandable and the efficiency, I'm thinking of the old times java. I've seen people in systems department having to profile java stuff because they were OOMing their tomcats. Eventually we had to ask for the code, debug it and send it patched with just some '=null' because the GC wasn't doing its job in the best way. In the early 2000 the philosophy already was "Good hardware is cheaper than expert developers" :(
About the code should be understandable and the efficiency, I'm thinking of the old times java. I've seen people in systems department having to profile java stuff because they were OOMing their tomcats. Eventually we had to ask for the code, debug it and send it patched with just some '=null' because the GC wasn't doing its job in the best way. In the early 2000 the philosophy already was "Good hardware is cheaper than expert developers" :(