In this paper we unpack empirical data from two domains within the Blockchain information infrastructure: The cryptocurrency trading domain, and the energy domain. Through these accounts we introduce the relational concepts of Blockchain Assemblages and Whiteboxing. Blockchain assemblages comprise configurations of digital and analogue artefacts that are entangled with imaginaries about the current and future state of the Blockchain information infrastructure. Rather than being a black box, Blockchain assemblages alternate between being dynamic and stable entities. We propose Whiteboxing as the sociomaterial process which drives blockchain assemblages in their dynamic state to be (re)configured, while related artefacts and imaginaries are simultaneously transformed, creating dynamic representations. Whiteboxing is triggered during disconfirming events when representations are discovered as problematic. Complementing existing historical accounts demonstrating technologies in the making, the contribution of this paper, proposes whiteboxing as an analytical concept which allows us to unpack how contemporary technologies are created through entrepreneurial activities.