10th house - this is the social status of a person, self-realization, career, relationships with superiors. Mercury - the intellectual planet, associated with thinking, contacts, connections, communications. Accordingly, a person with Mercury in the 10th house (in the highest house) should be maximally revealed in terms of intellectual abilities. The profession of such a person is related to communication, the sphere of information.
This is a good specialist in his field, in his business, where his Mercurian abilities are manifested. Mercury sees all the details, notices all the subtleties. And the person of his business perfectly understands all the details and nuances of his work.
He is able to collect and process information well, and then with pleasure can share it with others. But he will never spread information from dubious sources, as he can lose his reputation in the eyes of society. With such a position, there can be teachers, engineers, designers, inventors.
By the type of work organization, he is not a careerist, but an excellent performer (of course, if there are no other pointers). As a rule, he is on good terms with the management (closer to friendly), can always offer something useful, shine with his knowledge, mind, loves to conduct a conversation on a rational basis. There may be young bosses.
A person with Mercury in the 10th house is confident in his mental abilities, loves to demonstrate them to those around him and gain respect.
Such a person is eloquent, knows how to perfectly convey his thoughts to others. And such a person is listened to, his opinion is often authoritative.