I'm curious what other people would say about #4. The only two answers I've ever heard are to become a chief architect (that seems to be the only seniority path that isn't management), or just go into consulting.
Facebook (and probably many other companies) maintain an IC (individual contributor) track that doesn't entail becoming a manager or becoming some sort of architecture astronaut.
There are a few flavours of seniority for ICs - deep domain expertise, deep skill set, high productivity, high flexibility, able to design and communicate and drive large-scale changes, mentorship, and non-technical organisational leadership like running a training programme, improving hiring, and so forth.
There are a few flavours of seniority for ICs - deep domain expertise, deep skill set, high productivity, high flexibility, able to design and communicate and drive large-scale changes, mentorship, and non-technical organisational leadership like running a training programme, improving hiring, and so forth.