I would like to ask a question about seeking for a job. This job is outside academia, but require many academia skills (such as math, able to deep research, etc). Is this kind of question on topic here? If not, is there a site should I ask instead?
Broadly speaking, questions about job-seeking outside of academia are not on topic. You may want to try checking out Workplace.SE.
I'm sure there are some counter-examples where questions like this were on topic; if you find any that you want to have clarified, feel free to post in the comments and we can discuss.