What language are you porting to? Designs that worked in the prior language aren't usually applicable, or preferable, in another. People who are so heads-down

What language are you porting to? Designs that worked in the prior language aren't usually applicable, or preferable, in another. People who are so heads-down-get-shit-done can be writing the next-gen API in a way that they really shouldn't be, in consideration of language differences. Maybe you're more cautious? There are benefits for both types of personalities in a team, and one isn't better than the other. Your mental abilities aren't declining. You've got a lot more going on in your life than you used to.