Meta Phone screen

Meta Phone Screen

Questions:

1. Given r and N, print (x,y) coordinates of N points which would lie on a circle with radius r, centered at the origin.
2. Variation of Random Pick with Weight. Follow-up: How can you optimize it to do random pick in O(1) time?

The phone screen was successfully completed. I am now preparing for the onsite interview. I am seeking guidance on how to best prepare for the system design and behavioral interview components. Additionally, I would appreciate advice on the ideal timeframe to request for onsite interview preparation.