Piras, Enrico MariaFerro, Antonella2019-05-282019-05-282019‘Healthcare infrastructures’ is often associated with large, complex and costly technical solutions made available by institutions. The widespread use of smart devices made possible the development of information exchange building on general purpose communication technologies. Through the analysis of an expert opinion service for breast cancer via WhatsApp, we illustrate the process of setting up the service, the challenges and the ramifications of health information exchange taking place through non-institutional channels. We introduce the concept of ‘grassroot infrastructures’ to indicate socio-technical systems created and managed by lower-ranked organizational actors, invisible to rationalized representations of work.enText/Conference Paper10.18420/ihc2019_0132510-2591