We want a smooth import/export experience in our CRM so large datasets don’t tie up the app. Customers will upload big CSVs (thousands of contacts). The API should accept the upload quickly, return a tracking ID, and hand off the work to a background job. A worker service will validate and transform rows, then bulk upsert them into PostgreSQL under the correct tenant. Exports of large lists should follow the same pattern (background job or streaming) and shouldn’t affect overall performance. We also need endpoints to check job progress and results (queued, running, completed, failed), with basic per-row error reporting. Prefer a queue-based design to decouple the request from processing.