> I write the other code because I'm basically the domain expert I think this is a key point. In my experience there are two paths for engineers to senior leve

> I write the other code because I'm basically the domain expert I think this is a key point. In my experience there are two paths for engineers to senior level positions: (1) management, which is usually easier (more openings available, engineers may find it unattractive) but slowly moves one away from technology development, or (2) domain expertise which is technically harder to achieve (need to be recognized as expert) but often provides more freedom and allows staying science / technology focused. Each path requires some (different) soft skills which are more important than maintaining either a super broad or a super focused "stack". My 2c.