Chemical methods enable the synthesis of structurally defined proteins carrying various post-translational modifications, which supports the advancement of research in post-translational modification proteomics, biochemistry, structural biology, and drug discovery. How to synthesize various post-translationally modified protein domains in a shorter time (e.g., within days) and with higher efficiency (in milligram quantities) is a problem that needs to be addressed in this field in the future. Recently, we have focused on developing faster chemistry strategies to constantly improve the speed of chemical protein synthesis.