How many technical interviews taken if want to switch b/w EDA players

I was wondering how many technical interview rounds they take if we want to switch b/w Siemens EDA, Synopsys , Cadence. If the candidate is already working in one of this. And what is difficulty level of interviews any advice is greatly appreciated. Current Role at Synopsys: Sr R&D Engineer YOE:3 TC21.5#cadence #siemenseda #mentorgraphics #siemens #synopsys #synopsysinc #eda #semiconductor #interview