There were three interviewers, like most companies. Questions were about past projects, experience, and brain teasers.
One of them asked me how to do path search in my robotics projects. Another asked questions about numerical integration, like the aspects of Runge Kutta.
One brain teaser I remember is: Given a t-rex and a pack of sheep on an island, how large the island needs to be to keep all creatures alive? It was pretty open.
Probably some details of numerical integration.
The following metrics were computed from 1 interview experience for the Blizzard Technical Director role in United States.
Blizzard's interview process for their Technical Director roles in the United States is extremely selective, failing the vast majority of engineers.
Candidates reported having very good feelings for Blizzard's Technical Director interview process in United States.