A case study of how a Filipino migrant merged into her Hong Kong workplace where the local veterans employed code-switching at work, denotes that for a rookie, code-switching signifies socialization wish, membership negotiation, linguistic capacity, and professional skills, and that for a veteran, code-switching discloses situated identities, immediate relationships, receptivity to newcomers, and inspiration to them. It is argued that code-switching is executed by foreign newcomers and local veterans for the benefit of workplace socialization and mutual identification.