I think his point is that working on deep internals (rather than client facing products) is difficult to show off. I think this is true, because you would have

I think his point is that working on deep internals (rather than client facing products) is difficult to show off. I think this is true, because you would have to do extra work beyond what your being paid to do, to make it show-off-able. However, look at Brendan Gregg for example. He works on deep internals that would be very hard to show off without putting extra effort into sharing his knowledge. But since he does make that effort, he’s seen as an industry leader for his skill set.