Okay, I'm going to be the one to say it. I'm in the middle of my first-ever CRM migration (from a basic one to a more robust platform), and our new vendor swore up and down there would be "zero downtime." It sounded so smooth.
We went live last Friday evening. By Saturday morning, our sales team's custom activity reports were pulling in duplicate data, some contact fields we mapped just showed up blank, and the mobile app login was glitchy for a few people. Nothing catastrophic, but definitely *weird*. It wasn't "downtime" in the classic "system is down" sense, but it wasn't business as usual either. We spent the whole weekend checking things and sending notes to support.
This makes me think the promise itself is a bit of a myth, or at least we all define "downtime" differently. The core system was up, but the experience was messy. I'm actually glad we planned for a weekend launch.
For those of you who have done this before, is this just normal? What are the specific "weird" things I should have expected that aren't technically downtime? I'm trying to learn what's a minor hiccup versus a real red flag.
Oh, totally normal. The "weird" phase is almost a guarantee. Vendors define downtime as their servers responding to requests, not your business logic holding up.
In data pipeline work, we call this "data drift." Your mapping looked correct in staging, but the production data volume and real user concurrency expose edge cases. Those blank fields? Probably a null in the source that didn't match your transformation rule. Duplicate reports often mean a timestamp or incrementality logic in the sync was a few minutes off, creating overlapping windows. The login glitches for a few people sound like session cookie mismatches or cached asset problems.
Treat any major platform migration like deploying a new data pipeline: you need a validation period. Plan for a "weirdness budget" of 48 hours where someone is monitoring key reports and user flows, not just system uptime. The red flag isn't the weirdness, it's if the vendor's support tries to dismiss these as "not downtime" instead of helping you fix them.
Extract, transform, trust
Exactly. Their SLA is about infrastructure uptime, not your business continuity. The cost angle gets ignored.
Your "weirdness budget" is a direct operational cost. You're paying for weekend on-call staff, emergency vendor support hours, and lost productivity. That's a real financial line item vendors never quote.
Treat the migration contract like a cloud reservation. Negotiate credits for every hour your team spends cleaning up their "non-downtime" issues post-cutover.
cost per transaction is the only metric