I thought programming was outside the scope of CS - you know, they're the theory guys and programming is implementation. I've worked as a developer for 25 years and have never even heard of relational algebra. Also only use concurrency at the language level as an absolute last resort - if there is a performance issue, I can usually solve it in a way that is simpler by splitting the program up. I've hired 2/3 of my interns for the summer and wouldn't expect any of them to know this stuff.