The application and interview process is entirely online.
The first round is a 1-hour phone interview, and the second (final) round consists of four 1-hour video interviews. All interviews are conducted in a pair-coding format. The process is quite smooth.
I cannot disclose the specific question, but it's generally design and implementation-oriented. I did not encounter questions that require mental math.
The following metrics were computed from 1 interview experience for the Jane Street Software Engineer role in Japan.
Jane Street's interview process for their Software Engineer roles in Japan is extremely selective, failing the vast majority of engineers.
Candidates reported having very good feelings for Jane Street's Software Engineer interview process in Japan.