auditor; comptroller
Legal and corporate role: a person who audits accounts or oversees financial compliance. Often used in the context of companies, organizations, or government bodies.
supervisor; inspector; manager
General oversight role: someone who monitors, inspects, or manages operations. Less formal than the legal auditor sense, but still implies responsibility for checking or directing work.
As the company's auditor, he checks the financial statements every year.
At the construction site, the supervisor is checking safety.