On top of is an idiomatic expression that is often used as an adverb to describe being in control of a situation or aware of all aspects of it. Some synonyms for this expression include in charge, in control, on the ball, on the job, overseeing, supervising, and managing. Other alternatives to on top of include keeping an eye on, in the loop, up to date, with it, abreast, cognizant of, and knowledgeable. Whether you're managing a project, running a business, or simply trying to stay on top of things, incorporating these synonyms into your vocabulary will help you better communicate your level of involvement and awareness to others.