Current process: Codelist assigns codes to all records (for example 600,000 emails ≈ 4 hours at 150K/hour) before any emails are sent, causing significant delays.

Proposed solution: Implement batch processing to:

- Split customer selection into smaller groups (without using the split flow object);
- Process and send each batch independently;
- Allow parallel code assignment and email delivery.

This reduces wait times since early batches can begin sending while later ones are still processing codes.