What aspect of performance though? Even that means a variety of different things to different people and it isn't just algorithms. I've met people who are bad a

What aspect of performance though? Even that means a variety of different things to different people and it isn't just algorithms. I've met people who are bad at typical CS algorithms yet know their language of choice very well and write low-allocation high performance tight code that "does less". Or people that are used to handling concurrent code which sadly is still somewhat of a rare skill. Only the algorithms are touched on in typical CS courses; most aspects of performance tuning come from experience and persistence spending hours trying to get more performance and less resource usage out of an application.