The purpose of this paper is to understand why and how the concept of social sustainability evolves over time by generating a gap between the initially desired strategy and the daily practices at the city level. An extensive ethnographic study was conducted focusing on how social sustainability, as defined in the smart strategy of the city of Gothenburg, was first translated and then turned into practice. Through the lens of Actor Network Theory, findings reveal that the translation of a smart city strategy aimed at ensuring social sustainability depends on how the actors involved at various organisational levels interpret the concept of social sustainability and work to translate it into practice. Such translation takes different  directionsand may lead to a transformation of the concept itself which becomes foggier over time.