In this research-in-progress paper I show how individuals in a professional service firm passionately, and of their own volition, engage in work activities across multiple social media, that fall well outside of formal work requirements. I refer to the personas these workers create as “alter-identities” to signify that this form of identity work sits alongside formal work roles. Utilising a reflexive research approach, I set out to explore 1) how professionals maintain alter-identities and 2) implications vis-à-vis organisational expectations. I offer initial insights into the role of social media, and the ways in which individuals reconcile alter-identities with formal requirements. I will contribute new insights on the role of digital technologies, such as social-media, in knowledge work contexts, and theorise the role of alter-identity performance as a way for organisations to innovate formal work models in a bottom-up, employee-driven way. Such practices might foster organisational responsiveness in rapidly changing environments.