Fix Multi-Tenant NestJS Backend

I'm seeking an experienced NestJS developer to help resolve data isolation issues in our multi-tenant backend. We currently use a shared database with tenant-specific rows, and are facing concurrency issues.

Key Requirements:
- Expertise in NestJS and multi-tenancy
- Experience with shared databases and data isolation techniques
- Strong problem-solving skills to address concurrency issues

Ideal Skills:
- Background in database management, particularly with shared database architectures
- Familiarity with concurrency control mechanisms
- Ability to implement robust data isolation strategies

Please provide examples of similar work done.