lozzd

Generally, we use most of the power of a given machine, so it doesn't necessarily make sense. We have nothing against virtualisation, given the right workload: For example, we give every engineer a virtual machine (since it's unlikely all of them are using the full power of a machine), and continuous integration test nodes (because it's easier to have separate LXC containers to share resources than try and run multiple MySQL/Apache/etc on one host)

We're sticking with the classic, good old Nagios. It's semi-automated right now with host configurations, contacts and contactgroups populated from Chef, but manual configuration otherwise (version controlled in git)

We're running Cloudera's CDH open source release (specially CDH4.1 right now) Because we use Chef so heavily we decided to stick with the open source release since it's so easy to build new machines, and just install the RPMs/configs.

In answer to your part about scaling, it's manual (no cloud here) but given spare hardware we can spin up a machine using a command line tool (we hope to open source) using a Chef role in about 5-10 minutes, so it's not a huge pain.

I believe the kids are calling it "devops" nowadays :)

In all seriousness, yes there is a lot of overlap, and the answer is by purposefully maintaining that overlap. The team that handles this sort of thing, our "devtools" team, handle things like upgrading PHP site-wide, maintaining deployinator. They understand operations, but also the two teams lean on each other for support. Likewise, operations at this scale does involve a lot of coding ("engineering"), so really we're all involved. In fact, the two teams are actually both lead by the same person.