Frontend software engineer. Latency management is included in front-end engineer's job (because most of the time, it's Javascript's fault), so debugging something like this would not fall outside of the job description. My interviewer was also a frontend software engineer. Both of us ended up doing more general-SWE/TL jobs later on, though (by coincidence, I ended up on the same team as her a year and a half later).

I doubt that they would ask the same question now - for one, most Chinese queries are served out of datacenters in Southeast Asia now (at least when I left; if I believe the Project Dragonfly news I hear about on HN they may be served from inside China), so there's no trans-Pacific cable hop. The Chinese population has also gotten a lot more access to broadband & high-bandwidth mobile connections in the decade since this interview.