There were two phone screens.
The first phone screen involved solving two competitive programming-type questions, on the easier end of the competitive programming scale.
Once you passed that round, you entered host matching. The second and any following interviews were conducted by individual teams to assess how well you would match as an intern. Usually, they asked only very mild technical questions, if any.
Compare object-oriented programming in Java vs. C++.
The following metrics were computed from 60 interview experiences for the Google SWE role in United States.
Google's interview process for their SWE roles in the United States is very selective, failing most engineers who go through it.
Candidates reported having very good feelings for Google's SWE interview process in United States.