Google Software Engineer - Internship interview questions

Had two interviews, the first one was technical. The interview was over phone, shared screen, technical python interview. The interviewer was asking me to explain why I think my solution is good and how it can be optimized.

I applied online, was reached out by a recruiter to set up two back-to-back technical interviews. The recruiter was helpful and quick to respond. The two interviews went the same, first, tell me about yourself, then a coding question. They were easy-medium, I came up with the solution pretty quick but took too long to code. The second interview was with a first-time interviewer. He was very nitpicking. I was stopped in the middle a few times to change variable names and had to use constants instead of numbers (like 0 and 1) to flag.