One of the most critical issues of our time is sustainability. Simultaneously, techno optimism is prevailing in public discourse suggesting that technology will create a sustainable future without requiring drastic changes. Despite the connection that is often drawn between technology and sustainability and the presence of technologies in organisations, research combining the two concepts remains limited and does not account for the interplay of social values and technological artefacts. To overcome this incomplete picture of technology, this thesis employs sociomateriality to investigate how sustainability and technology are understood in relation to each other by young sustainability practitioners in for-profit organisations. Following the social constructivist philosophy, nine semi-structured interviews were conducted which show that practitioners recognise the environmental and social limits to development and use the triple bottom line (TBL), consisting of economic, environmental and social dimensions to translate sustainability into organisations. However, TBL implementation varies between organisations showing the difficulty of unifying organisational sustainability in one concept. Furthermore, young sustainability practitioners understand technology as sociomaterial, describing the interplay between an artefact’s affordances and restraints, and the practitioner’s configuration work that co-create outcomes. Moreover, the interviewees are optimists not because they rely on technology, but they believe in human’s ability to change which differs from techno optimism. It can be concluded that practitioners are critical about relying on technology for sustainability and believe that sustainability is created through an interplay of humans with technology, transferring responsibility to humans. When it comes to creating a sustainable future, they first struggled to envision an alternative future beyond technological developments but started imagining when given space to reflect. One outcome of the research is that young sustainability practitioners must be given room to reflect on their understanding of sustainability, technology and their relationship as the first step to taking actions to create the future.