Migrating a Single-Tenant SaaS to Multi-Tenant Workspaces with EF Core Global Query Filters

TL;DR We had a single-tenant Angular + .NET 10 SaaS where every row was scoped by UserId . To support firms (multiple lawyers sharing data), we needed multi-tenant workspaces — but rewriting every query was off the table. EF Core's HasQueryFilter made it possible to flip 9 tables to multi-tenant in a single weekend, with zero query call sites changed. Here's the pattern. Context I'm building NeoJurídico , a court-process monitoring platform for Colombian lawyers. Plan Bufete users need to share