Google Software Engineer - Internship interview questions

Coding snapshot with two questions; seems like passing all test cases for the first was enough to move onto next round. Next round was two (back to back) 45 minute phone interviews with Leetcode Easy (2x) and Leetcode Medium questions.

Two rounds back to back. Each round is 45 minutes. First round I was asked two questions. First one is adding two strings. Second one is a class design question.