- a person who belongs to a profession occupied with, e.g. maro (“sea”) + -isto → maristo (“sailor”).
-isto is not as broad as English -ist.
It is important to distinguish between an -anto, someone who is doing something, and an -isto, someone whose job it is to do something. For example, if you are cooking dinner, you are a kuiranto (“cook (someone who is cooking)”). If you are employed as a chef, you are a kuiristo (“cook (by profession)”).