Just wonder this is your first job or not. If it is your first job, technical review will test your technical communication skills. If not, some questions will fall on your lastest work in Canada. More questions will be around your applied position in this company, like an engineer using C to control step motor, you should know how to send pulse, the relationship between pulse freq and motor speed, S curve and encoder close loop etc.
It is strange that three interviews are arranged together. Don't know the exact reason. Maybe they want to locate the right person ASAP.