C might have pointers, Python has efficiency gotchas.
It might have heap allocation, Python has numpy.
Rust might ...
Even so, while there _may_ be more technical scope in some languages, or more immediate surface area, this should be true:
A senior developer primarily in language Y should be technically capable enough to be senior in language Z with some degree of work.
The language isn't relevant. Data structures, engineering mindset, pragmatism, intuition, maths reasoning, abstract thinking, ...
These are things that make a senior developer.
If I find a Python dev without this skillset at a high level they're not being put in a senior position because they'll add technical debt, cost and risk without even knowing it. They're a liability.
Your "senior" Python developers don't sound senior to me.
If you think you can promote anyone to senior or principal without the above, you're a liability too. Good job.
It might have heap allocation, Python has numpy.
Rust might ...
Even so, while there _may_ be more technical scope in some languages, or more immediate surface area, this should be true:
A senior developer primarily in language Y should be technically capable enough to be senior in language Z with some degree of work.
The language isn't relevant. Data structures, engineering mindset, pragmatism, intuition, maths reasoning, abstract thinking, ...
These are things that make a senior developer.
If I find a Python dev without this skillset at a high level they're not being put in a senior position because they'll add technical debt, cost and risk without even knowing it. They're a liability.
Your "senior" Python developers don't sound senior to me.
If you think you can promote anyone to senior or principal without the above, you're a liability too. Good job.