alt Hacker NewsWithin a given company, I think these roles are well-defined. In a big tech company, a principal engineer will influence decisions at a much higher level then a senior whose isn't visible outside his team. And an engineering manager support, evaluate, represent the team, and help with goal alignements.
Maximally cynical take, tongue somewhat in cheek:
If we measure principal engineers by "cross team force multiplier impact and its visibility to management" (second part being key), what kind of behaviors do we incentivize? Are there, possibly, bunches of mid-level and senior engineers dealing with extra hassles to demonstrate this impact?