Why Unified APIs Aren't Enough: The "Sync Logic" Trap 🕳️

If you’ve ever built a CRM, an ATS, or a Project Management tool, you know the drill. A customer asks for "Google and Outlook integration." You look at the APIs, realize they are wildly different, and decide to use a Unified API . It feels like a win. You have one schema for contacts, one for calendar events, and one for emails. You think you’re 90% done. You aren’t. You’re actually about 10% done. The hard truth that many developers learn the hard way is that connectivity is not synchronization. While a unified API handles the "handshake" and the data mapping, it leaves the most expensive, bug-prone part of the project—the Sync Logic —entirely in your lap. 1. The "Lowest Common Denominator" Problem Unified APIs are great at normalizing data, but they often strip away the "behavioral" intelligence of the underlying provider. Take Calendar Recurrence . Google and Outlook handle recurring events (and their exceptions) differently. A unified API might give you a standard JSON object for a