Combinatorics and graph theory have zero to do with this practical knowledge. I'll grant that computer architecture classes introduce some relevant concepts, but this foundation can be had from anywhere as its matters, history, and details are widely discussed in the open online as a persistently current practical concern.
People like the author, with a degree and lots of experience under their belt, really overestimate what the degree specifically gave them, vs what they learned through decades of experience as they developed their craft. When it comes to practical, applied programming and skills of abstraction, informed by deep knowledge of what goes on under the hood, vanishingly small amounts of that come from university education.
Again, I will be careful to separate out those who do actual Computer Science on the job from this practical craft of quality programming. The former is much more rare, but is a separate field.
People like the author, with a degree and lots of experience under their belt, really overestimate what the degree specifically gave them, vs what they learned through decades of experience as they developed their craft. When it comes to practical, applied programming and skills of abstraction, informed by deep knowledge of what goes on under the hood, vanishingly small amounts of that come from university education.
Again, I will be careful to separate out those who do actual Computer Science on the job from this practical craft of quality programming. The former is much more rare, but is a separate field.