The Marie-Skłodowska-Curie European Doctoral Network BiocatCodeExpander is focused on expanding the diversity of functional groups present in proteins to enhance the fields of biocatalysis and biotechnology by using non-canonical amino acids as building blocks. For this, BiocatCodeExpander brings together experts from synthetic biology, biocatalysis, computational biology, structural biology and organic chemistry to ensure the development of methodologies in a collaborative manner and with a strong participation of the private sector.