There are plenty of synonyms for the phrase "doest business." Some common ones include "conducting business," "operating a company," and "running an enterprise." Other possibilities might include "managing a venture," "working in commerce," or "engaging in trade." All of these phrases generally refer to the act of carrying out transactions, whether it be buying and selling products, providing services to customers, or simply managing the day-to-day operations of a business. Depending on the context, different synonyms may be more appropriate, but all convey the same general meaning of engaging in commercial activities.