We reflect upon the process of developing a tangible space for children's collaborative construction of screen-based systems. As in all design work, the design process involved continual refinements of initial ideas and their practical realisation. We discuss how some widely held assumptions often put forward with tangible interfaces were given up in favour of reaching overall goals of interaction. In particular our design involved a shift from a focus on persistent representation and readability of tangible code structures, to instead focus on achieving reusability of programming resources. On a general level, our results illustrate a view on tangibles as resources for action instead of only as alternative forms of data representation. Importantly, this view includes action directed towards the computer as well as off-line socially oriented action conducted with the tangible artefacts.