story
> The primary skill of senior engineers is to train junior engineers. If you’re senior with no junior around, you’re not senior.
and
> Under that lens, the term “junior” just means “someone who has done less, and/or has less experience with, a specific task or tasks in a specific domain”, by contrast with “senior”. In other words, junior/senior is domain-dependent and team-dependent: we can be senior in one field (e.g. databases, containers), junior in another (e.g. frontend, machine learning). We can be senior relative to one team, and junior relative to another.
To suggest that you're not a senior developer because you take you're effected negatively by a lot of context switching is just blaming your manager's problems on you. Using a situational[2] senior position, you surely would meet the requirements. Note that neither of those deal with iteration speed or context switching, what a stupid metric.
Maybe you would do better in an actual senior role where you're doing more mentoring/overseeing rather than direct coding and bouncing around in tons of different code bases.
[1]: http://jpetazzo.github.io/2018/08/15/junior-senior-mentor/
[2]: https://en.wikipedia.org/wiki/Situational_leadership_theory