Who exactly defines the internal flows of the city, and what happens when this 'flow' is rendered bottom-up? Rather than exploring the ways in which the digital affects the organisation of the city, in this paper, I aim to show how certain smart systems of coordination - based on a non-digital 'smartness' - exist in parallel to the increasingly digital smart city today. Various forms of improvised coordination and humanled calculation are an integral part of the smartness of a city and must not be overlooked. Drawing on ethnography of train ticket sharing networks in Germany, this paper explores the assemblages of human and non-human, digital and analogue actors that can attach themselves to an existent system, acting as 'parasitic infrastructure'. Understanding how these parasitic infrastructures emerge highlights how systems of calculation and computation exist beyond just the digital.