api gateway vs direct service calls: when to introduce an abstraction? dont wait too long. it can get messy.

hey folks, i've been thinking about api design recently. we're a growing microservices setup, and right now, services just talk straight to each other. it's worked out okay, but i'm starting to feel the pain with managing things like auth, rate limiting, and request tracing across the board. would an api gateway be the next logical move here, or are there times when direct calls are still better, even when things get big. what's your experience been, and when did you decide to add that extra layer