Considering the complexity and practicability, re-engineering instead of de novo design is still the main strategy in synthetic biology. However, for exploiting the full potential of synthetic communities, artificial systems built from synthetic parts and organisms need to be considered more broadly. Of course, complexity increases non-linearly with the number of synthetic parts and organisms which are combined. Therefore, the de novo design relies heavily on computational guidance to obtain microbial consortia with higher efficiency, stability, and controllability. Intertwining mathematical modelling and bioengineering right from the beginning will be key to accomplish a successful, fully synthetic community design.