Engineering microbial biofactories for the transformation of industrial residues into value-added products represents a significant step toward sustainability. This chapter has two main goals: first, to review the current approaches that can be used to engineer synthetic biofactories of relevance for white biotechnology, and second, to provide clear examples of how these biofactories represent an excellent platform to transform industrial residues into value-added products. Several technologies used to engineer microbial biofactories (e.g., BioBricks design, pathway engineering, modular assembly, and chassis fine-tuning) will be discussed using a multiscale approach from genes to biofactories. The relevance of omics databases for the identification of novel biological components (genome mining) and fine-tuning their expression will also be discussed. Finally, several examples will be provided to highlight the relevance of engineering microorganisms as biofactories for a sustainable future.