It doesn’t take 3 months to do this even at wholly internal faang environments except in some special cases.
Most of what people are talking about can be learned in days because they’re 90% the same as other products. Sometimes it's hours as someone else said because they're just generic databases or a pubsub system.
And then you get an edge case bug with the new platform and the new guy takes N times longer to find the root cause because it's his first time using the platform.
Or the design is wonky because the new platform isn't a 1:1 match to the proprietary solution.
Most of what people are talking about can be learned in days because they’re 90% the same as other products. Sometimes it's hours as someone else said because they're just generic databases or a pubsub system.