It depends. If you are referring to a specific job title such as “Head of Digital Marketing” then you should capitalize the job title with regular title capitalization rules since it is a proper noun.
However, if you are referring to a general job title in a sentence such as “program chair” in the following Objective Statement: “I am seeking a position as a program chair,” then you should lowercase the job title.
These rules even apply to executive titles at a company.
For more help with capitalizing job titles and other resume sections, refer to our guide on resume capitalization.