ccs-hack
CCS (Customized Constraint System) is a generic constraints representation system can simultaneously capture R1CS, Plonkish, and AIR:
You can easily convert CCS to R1CS, Plonkish, Air and vice versa. You can also build proof systems that directly using CCS as the constraints system, such as HyperNova, SuperSpartan.
CCS can save (or add) the fragmentation of arithmetisations!