It was a 3 round interview process
2 Technical, 1 Techno Managerial, and last HR round.
My interviews were for C# Fullstack Developer
they asked the basics of C# like middleware, service lieftimes, LINQ, etc.
We usually tend to forget the basics and jump on the advance topics for the interview prep.
But the most you should focus on is the basics for any C# dotner interview.
OOPS concepts, and SOLID principle.