Job interviews can be very different from country to country. An interviewer's "body language" and questions, and the form of an interview are not the same around the world.
If you are at a job interview in Japan, don't look directly into the eyes of the interviewer. It is considered impolite. But if you are at an interview in the US, you should make eye contact with the interviewer. If you don't, the interviewer may think you are not sure about your ability.
In the US and some other countries, interviewers aren't supposed to ask questions about family and personal information. In more countries, interviewers aren't supposed to ask questions about family and personal information. In more countries, personal questions are very common during job interviews.
In Germany, your interview might begin with a very short conversation followed by a formal interview. In Mexico and many other countries, the whole interview might not be formal.