Maybe you've been more lucky than me, but I've seen plenty of such "junior devs" in positions of influence, with titles such as "senior" or "principal" dev, "ar

Maybe you've been more lucky than me, but I've seen plenty of such "junior devs" in positions of influence, with titles such as "senior" or "principal" dev, "architect" or "engineering manager". In many places, titles like that accrue automatically as people get older, especially if they play the political game reasonably well. Some of them will then happily do what you correctly label "Premature optimization" in the microcode, but proceed to make big mistakes in the overall design that leads to several orders of magnitude slowdowns in the general design. I believe the problem is in the training. As junior devs, they may have been scolded for premature optimizations of microcode, but worked within a well thought-out design at the macro level. Then they advance in ranks, and have to do the design part as well, but they never learned to think about the performance at that level, something that benefits a lot from some contemplation up front.