How do you decide between learning a new stack yourself versus bringing in someone who already lives in it every day?

Man, I've been there more times than I can count. A couple projects back we had this tight deadline on a Python-heavy backend revamp, and honestly, our main guy was more of a JS person. He could've powered through and picked it up, but we figured the ramp-up time would've killed us. Instead we looped in a dedicated dev who was already knee-deep in that ecosystem—super smooth handover, no rookie mistakes slowing things down. In the end it saved headaches and let the rest of us focus on what we actually knew best. Sometimes bringing in syndicode dedicated software developers makes sense when the niche is deep and the timeline's unforgiving, you know? Just my two cents from seeing both sides play out.