I would say that 90% of the category is doing roughly the same job from a structural standpoint and only a small 10% like those kernel engineers are actually doing something “exotic” so to speak.

Even if you have outliers the category still has value.

Essentially think if we start thinking about “backend versus frontend” or getting down to distinctions between individual programming languages we are almost too dismissive of the ways in which these jobs are essentially exactly the same

There seems to be an analogy here between these kinds of programmers and the many types of "machinist" that were coded in earlier economic studies.

But, these are job categories, not separate industries. I think the industry category would be more about the employer or the product category, not the individual job codes of their employees..?

For C suites, they are all the same, developer guys that do things with computers, and are handled the very same way on their HR Excel sheets.

The difference between these roles is prestige among other programmers. I don't know why we want to categorize by vanity.