Systems Architecture

The PhysicalArchitecture? of the system: what does our network look like, should we use hardware load balancing, should our database server be clustered, do we need a 4-way or an 8-way machine here, is it ok to put a firewall between the web server and the application server, should we throttle the threads on the tier 1 application servers, how big should our pipe be into the POP ...

I don't know what all this stuff means but this is what the people accross the corridor talk about. Its a completely different language to that used by the people in SoftwareArchitecture which doesn't seem right to me, but I'm JustaProgrammer. How much should I care?