Your job descriptions list a lot of technologies but dont mention anything to do with operating systems or networking. It seems odd to explicitly call out Node and redis but not anything down the stack.
It's a good point, but right now we don't do anything that relies specifically on one technology at the very low levels (for instance, kernel modules or very specific networking optimizations we don't need and would be over-optimization).
Instead we try to maintain a SOA which is agnostic to what underlying tools back our services, something that we've found Docker is useful for.
That being said, we generally just use Ubuntu, and have some other AWS-specific setups around networking. If you like hacking on Cisco routers, I think it's perhaps not the right position :)
I don't think there's anything wrong with that. Anyone in a sysadmin or devops is going to be expected to be proficient at Linux and bash, Windows and Powershell for Windows desktop/server admins, Cisco and Juniper for networking, etc. These are kind of default assumptions for positions like these.
More modern and highly specific technologies like HAproxy, Salt, Node, Redis are not going to be known by every experienced, competent applicant though, and while you can often pick them up on the job if you have general experience in the area, there's always going to be a learning curve.
I interviewed for a DevOps role at Clever a few months ago and the interview was 100% python algorithm questions. I did it correctly and was told how do I make it faster.. So I did and was told.. how can I make it faster.. After 30 minutes of a skype interview I told the guy I wasn't interested and thanked him for his time.
