Is it permissible to work for a company that manufactures coffins in non-Muslim countries?

It is disliked for a Muslim to be buried in a coffin unless there is a benefit, and the original method is for a Muslim to be buried in a niche (lahd) or a trench (shaqq). As for non-Muslims, they are not obligated to follow the Sunnah (definition) of Muslim burials. There appears to be no Sharia (definition) impediment to manufacturing coffins for burying non-Muslims, as long as they do not bear religious symbols specific to them. It is permissible for a Muslim to work in digging graves for the People of the Book, though if another job is available, it is preferable to leave this one.