I mean they are one of very few companies who have done arch changes like this and they had already done it twice before Rosetta 2. The same engineers might not

I mean they are one of very few companies who have done arch changes like this and they had already done it twice before Rosetta 2. The same engineers might not have been used for all 3 but I'm sure there was at least a tiny bit of overlap between 68k->PPC and PPC->Intel (and likewise overlap between PPC->Intel and Intel->ARM) that coupled with passed down knowledge within the company gives them a leg up. They know the pitfalls, they've see issues/advantages of using certain approaches. I think of it in same way that I've migrated from old->new versions of frameworks/languages in the past with breaking changes and each time I've done it I've gotten better at knowing what to expect, what to look for, places where it makes sense to "just get it working" or "upgrade the code to the new paradigm". The first time or two I did it was as a junior working under senior developers so I wasn't as involved but what did trickle down to me and/or my part in the refactor/upgrade taught me things. Later times when I was in charge (or on my own) I was able to draw on those past experiences. Obviously my work is nowhere near as complicated as arch changes but if you squint and turn your head to the side I think you can see the similarities. > Or were they just lucky to have success both times? I think 2 times might be explained with "luck" but being successful 3 times points to a strong trend IMHO, especially since Rosetta 2 seems to have done even better than Rosetta 1 for the last transition.