A field decision from a real production migration — not a feature-matrix blog.
When we migrated two internal enterprise applications (plus an integration layer) from on-premises SQL Server to Azure, the single most consequential decision in the whole programme was not the App Service tier, not the CDN, not the CI/CD design. It was the database platform. Azure gives you two serious PaaS options for SQL Server workloads — Azure SQL Database and Azure SQL Managed Instance (SQL MI) — and almost every comparison article online reads like a spec sheet. This post is different. It's the actual reasoning I went through, the evidence I gathered, the objections I had to answer during architecture review, and the trade-offs I knowingly accepted.
If you're staring at the same fork in the road, I hope walking through my decision saves you a few weeks.
The starting point: what we were actually migrating
Context matters more than features, so here's ours:
