Miriam Z.

Responsibilities:

• Part of the infrastructure team, responsible for making the multi-tenant security model usable end-to-end across the Flow Management Platform backend.

• Integrated backend services with existing PostgreSQL Row Level Security (RLS) policies by ensuring that all queries run with the correct tenant context, rather than defining the RLS policies themselves.

• Designed a tenant-aware context using a PostgreSQL GUC (app.tenant_id) together with custom EF Core transaction interceptors so each request opens a new transaction, sets the correct tenant, and avoids leaking tenant context through the connection pool.

• Designed and configured separate “admin” and “default” connection strings so that migrations and special admin operations can safely bypass RLS, while all normal business queries remain fully RLS-enforced.

• Implemented a tenant-aware secure login function that uses an admin connection during authentication to validate the user, resolve the correct tenant, and issue a JWT containing tenantId.

• Integrated end-to-end tenant propagation by wiring tenantId from the React frontend (JWT) through NestJS REST APIs into Apache Kafka topics and finally into a .NET data-processing worker, so all background processing runs under the correct tenant.

• Research: Analyzed PostgreSQL connection pooling and GUC behavior to prove that a new transaction per EF Core request is required to prevent tenant context from “sticking” between requests.

• Helped define and implement a cross-cutting Event service that publishes and consumes tenant-aware events over Kafka across multiple backend services.

• Supported other feature teams by explaining the multi-tenant model, reviewing their queries and APIs, and guiding them on how to adapt their code to work correctly with RLS and the tenant GUC.

• Validated multi-tenant security, login flow and RLS behavior in a Docker / Docker Compose environment and collaborated via Git/GitHub pull requests and code reviews under the guidance of an industry mentor and tech lead.