My favorite subjects in under/graduate school were things like operating systems, networking, filesystems, and databases. I rather enjoy worrying about memory/performance and my current skill set revolves around optimizing existing code. However, it seems to me that most of the new job postings that are "infrastructure" related seem to be writing wrappers around AWS/GCP/Azure services. Even within FAANG companies, it appears to me that the teams working on these systems are few and far between.
Where can the bulk of this type of work be found? Has the computing world solved most of these problems and moved on or am I not looking in the right places?
A lot of trading companies for instance will be looking for people like you. (In fact; i'm hiring people like you).