At least an onsite interview typically includes expense reporting lunch, if not dinner, and maybe an opportunity to visit a city or a part of city you are less familiar with and possibly even sight-see a bit.
I don't think a phone screen is productive beyond a half-hour to an hour and anyone asking technical implementations over the phone is likely a worse interview than trying to whiteboard things (and that's still far and removed from actual programming).
I don't think a phone screen is productive beyond a half-hour to an hour and anyone asking technical implementations over the phone is likely a worse interview than trying to whiteboard things (and that's still far and removed from actual programming).