noun
responder; handler; person who deals with a matter
Refers to someone who takes charge of an inquiry, incident, or task; often used in business or customer-service contexts.
See also: 対応
お問い合わせの内容は、担当の対応者から折り返しご連絡いたします。
Regarding your inquiry, the person in charge will get back to you.
noun
Used for a person or entity that corresponds to another in a different organization, system, or context; similar to a contact person or equivalent role.
See also: 対応
海外支社の対応者とメールでやり取りしています。
I'm corresponding by email with my counterpart at the overseas branch.
Compound of 対応 (たいおう, 'correspondence, handling') + 者 (しゃ, 'person'). The meaning follows straightforwardly from its components.