I will audit your multi tenant saas for tenant isolation and data leaks

Multi-tenancy does not fail loudly. It fails on a Tuesday, when one customer opens a report and sees another customer's data - and you find out from them, not from your logs.

WHAT I CHECK

Every query path that should be tenant-scoped and is not. Repository and EF global filters bypassed by raw SQL. Cache keys missing the tenant ID. Background jobs running under the wrong tenant context. Realtime hubs broadcasting across tenants. RBAC checked in the UI but not in the API. File storage paths that are guessable across tenants.

You get a written report, findings ranked by severity, each one with the file, the line and the concrete failure it causes.

WHY ME

I have built three multi-tenant B2B SaaS products in 5+ years - a CRM, an HRMS and a task management platform - covering tenant isolation, per-tenant config, tenant-scoped RBAC with deep permission trees, subscription plans and limits, per-tenant Hangfire jobs and SignalR. I now lead a team of 4+ developers.

Stack: .NET / C#, ASP.NET Core and Web Forms, Angular, MSSQL.

I will tell you when your isolation is already fine. That is a valid result and you still get the report.