We also have a wealth of knowledge about computer architecture and what software design decisions will result in performance problems or benefits. At a high lev

We also have a wealth of knowledge about computer architecture and what software design decisions will result in performance problems or benefits. At a high level, trying to design, eg, a computer vision application that has to upload gigabytes of data to the cloud, will result in poor performance. At the low level, iterating over linked lists is slower than memory contiguous arrays, especially if your data is too big to fit in cache. The low-level knowledge that inlined methods let the compiler eliminate branches and vectorize code more effectively, informs the mid level architects that if everything is done by inheritance you lose this advantage since everything has to go through the vtable. For too long we've been able to make poor performance decisions and be rescued by Moore's law; no more. We will find in the upcoming years that performance is an architectural decision that can come back to bite us if we don't design for it up-front.