I'm planning to interview for an SDE role with one of the Fintech firms, however they allow only these choices(Java, C, C++, Python) for their online assessment and interviews. I'm being allowed to use my language of choice everywhere else I'm interviewing and it just seems an overstretch to learn another language just for the sake of interviews, taking my focus away from the actual interview prep. Is it a fair ask to let them interview in my language of choice(C#) as long as I'm able to explain what's going on in the code?
Is this TS asking for one of those four?
Java and C# are basically identical so it shouldn't be an issue
You are free to use "commonly" used languages. If yours is something not mainstream then the company could potentially deny it.
Definitely unless the role is language specific.