Mechanical engineering taught me to look for the constraint. Cloud economics was the same habit with a different unit. Applied AI is the same habit again, with more uncertainty about what the unit even is.
The transferable part is the method
Domain knowledge expires. Problem structuring does not. Every move I have made kept the method and replaced the vocabulary, which is far cheaper than it sounds from the outside.
What actually costs time
Not the learning. The credibility. You rebuild that by shipping something small and specific in the new domain before claiming any of it in a title.