We actually have a set of criteria for what makes a qualifying systems elective. As with many things at CMU, we don't generally care what details you learn. W

We actually have a set of criteria for what makes a qualifying systems elective. As with many things at CMU, we don't generally care what details you learn. We care greatly what higher-level concepts you get exposed to, and the systems courses are the place we try to focus on the development of abstractions; modularity; isolation; reasoning about failures and complexity; integrating security concerns. They're also the courses where students are required to work on projects large enough to blow out their cache -- multi-week or month projects that force you to think reasonably about how you divide your design into pieces so that you can coherently reason about the ensemble. We're pretty much equally happy if you hit layering in the network class or thinking about the filesystem and kernel VFS layers in the OS class - or the modular structure of a modern compiler. Tackling the idea of reliability through replication in distributed systems (via a lot of different mechanisms, but with a decent dose of Paxos), or via the Reliable Storage module in 15-410, or in DB. Getting additional hardware architecture exposure through compilers or the parallel class. Thinking about communication using a fast local interconnect (parallel), the internet (networks & DS), or IPC (OS). Compilers can be more or less of a systems course depending on who teaches it, but it's generally got such a strong architectural component that it flies. It's much like programming languages. We don't care much if you graduate knowing a particular language -- any CMU CS graduate should be able to pick up a new language in short order. We care greatly that you've been exposed to a mix of programming styles and thinking -- imperative, functional, and logical or declarative, and can successfully use those tools to reason about code, program structure, algorithms, and data structures. So no, we absolutely don't consider it critical that you take any specific systems course, but we do consider it critical -- for the CS major -- that you be exposed to the broad set of systems concepts we teach in them. That's why we start them in 15-213 and then reinforce them with one upper-division systems elective requirement.