[dudul]

Sorry if it sounds a bit harsh, but saying that changing stack would lower you from staff to middle engineer is idiotic.

A staff engineer is meant to be more removed from the code than an intermediate engineer, they're supposed to bring massive multiplier effect instead of cranking code all day. I don't think you should focus so much on the stack.

[tuyguntn]

You're absolutely right in terms of what is expected from Staff eng, but try to get a job in companies with primarily Java or .NET stack (I am talking mostly about Western Europe).

First barrier is an interview, from my experience people expect you to know nitty-gritty details of their stack if you want to lead other engineers and be a force multiplier. How do you even do a code review without properly understanding the trade-offs in that stack or widely accepted best practices in the community, which you accumulate over a long period of time.

You can of course fallback to another archetype of staff eng, and become a voice of leadership to translate high level business objectives to technical solutions, but companies I know still expect you to write a lot of code

[nequo]

If you are interested in developing your career in that direction, would it have a higher reward in terms of job security and compensation to focus on your soft skills instead of hard skills?

If you're already a staff engineer, your leadership skills could be more important to your future than becoming fluent in Java or .NET. Aim for getting promoted, not for avoiding getting demoted?