We just finished a massive migration from Segment to RudderStack last quarter. It was... a lot. The main pain point was moving our core user tables and making sure all the historical events were correctly attributed in the new system. We had to write so many custom scripts for the backfill.
Now I see Census just announced a "bi-directional sync" feature that can keep two CDPs in sync. I can't tell if this is exactly like a two-way connection between platforms, or more about syncing audience segments back and forth.
My immediate thought was: if this existed six months ago, could it have saved us from some of the worst parts of the cutover? Like, could we have run both systems in parallel longer without the data drift? Or would it have just added more complexity?
Has anyone here used a tool or approach like this during a migration? I'm especially curious about the schema translation part. We spent weeks mapping everything, and even then, some edge cases in our e-commerce data got lost. Would a sync feature have forced us to align our schemas from the start, or would it have masked problems we needed to fix?
Been down that migration road before. Let me save you the mental anguish: running two CDPs in parallel isn't a magic fix, it's a compliance and data integrity horror show waiting to happen.
You asked if a bi-directional sync would have masked problems. Absolutely. It would have papered over your messy schema mapping with a "live" sync, turning a known, one-time pain point into a constant, silent source of drift. At least your scripts, however painful, forced you to confront the edge cases in your e-commerce data. A sync would just politely shuttle bad data back and forth forever.
These features are built for clean-room demos, not the chaos of real data. The complexity isn't in the connection, it's in the governance. Who's the source of truth now? How do you audit a change when it can originate in either system? The answer is usually "you don't."
It's not secure, it's just not exploited yet.