Three months ago, I rebuilt an internal dashboard API that was drowning in REST endpoints. Twelve different endpoints to fetch user data, project data, team data, and their nested relationships. The mobile app was making 8-9 round trips per screen load, burning through battery and data plans. I switched it to GraphQL. One endpoint, one request, exactly the fields the client needed. The mobile team stopped complaining about loading spinners. But last week, I built a new webhook integration for Stripe. Pure REST. Why? Because sometimes the older pattern is still the right pattern. The "GraphQL vs REST" debate isn't about which one wins. It's about knowing when each one fits. In 2026, I'm seeing more teams use both in the same system, and that's not a cop-out — it's smart architecture. Here's what I've learned from running both in production, backed by real performance data and the mistakes I made along the way. GraphQL and REST Explained: Core Differences The syntax differences are the easy part.…