  Workplace social media platforms enable employees to cultivate their
professional image and connect with colleagues in a semi-formal environment.
While semi-formal corporate communication poses a unique set of challenges,
large language models (LLMs) have shown great promise in helping users draft
and edit their social media posts. However, LLMs may fail to capture
individualized tones and voices in such workplace use cases, as they often
generate text using a "one-size-fits-all" approach that can be perceived as
generic and bland. In this paper, we present Corporate Communication Companion
(CCC), an LLM-empowered interactive system that helps people compose customized
and individualized workplace social media posts. Using need-finding interviews
to motivate our system design, CCC decomposes the writing process into two core
functions, outline and edit: First, it suggests post outlines based on users'
job status and previous posts, and next provides edits with attributions that
users can contextually customize. We conducted a within-subjects user study
asking participants both to write posts and evaluate posts written by others.
The results show that CCC enhances users' writing experience, and audience
members rate CCC-enhanced posts as higher quality than posts written using a
non-customized writing assistant. We conclude by discussing the implications of
LLM-empowered corporate communication.
