Information and Communication Technology (ICT) is one of the key enablers for including underserved communities in economic and societal development across the world. Our research analyzes several banking service projects developing technical solutions for rural India. This poster presents an experience report based on systematic debriefing of involved project leaders and initiators, triangulated with additional documentation. The concept of Socio-Technical Prototype is developed and used to show how to mitigate the challenges of ICT based banking service provision for socially constrained communities. The concept of Socio-Technical Prototype extends the notion of prototypes, as it implies a full functioning implementation of the service including all relevant stakeholders. In order to not only prototype end-user functionality but also the interaction of the solution with the specific social, technical and physical environment. The implications for software engineering in the development of such large-scale prototypes and pilots are outlined. © 2017 IEEE.