FAA EASA
Be it MCAS in this case or not, the MCAS certification of the MAX series smells. To certify a system that directly controls primary flight surfaces AND that is reliant on a single sensor (AOA), is against written and unwritten rules in aircraft design, engineering and certification. If we were not living in times of massive commercial global rivalry (US, Europe, China) I would have expected the FAA and subsequently EASA coming under enormous public and political pressure how they ever had accepted the MCAS certification proposal by Boeing. But it had become a political and commercial case where no country wants to damage its industry and protects its agencies. This is too sad as it damages the culture of aviation safety in lieu of local interests.