Google

Excellent internship.

First half of the internship was more research-oriented (prototyping systems, trying different algos, etc.). Second half focused heavily on core SWE concepts and merging in high-quality code.

Excellent opportunity for a PhD student interested in coding and system-building (i.e., industry): mentors were great, and I learned how to write great code, which isn't a skill that grad school usually teaches. All the insane Google perks (food, housing stipend, free tech) also didn't hurt.

Not a great fit if you're mainly an academic or looking to publish papers, though.

The only con is that the recruiters for my return process didn't quite seem comfortable with handling things, and sometimes got confused or gave me information that wasn't true.

The internship was still great; just make sure you stay on top of your recruiter afterwards.

They also cancelled my return offer due to COVID-19. This really isn't Google's fault, but I do know a few other companies that managed to keep interns in the pipeline remotely. Just a small footnote if it matters to you: this is a factor outside the internship itself, so I didn't incorporate it into the rating.