Need a Bulk Promo Code Generator for Email Campaigns

We are looking for a developer to build a tool that generates large batches of unique promotional codes in a single click, for our upcoming email marketing campaigns. Right now our team creates codes manually in spreadsheets, which is slow, error-prone, and impossible to scale once we send campaigns to segmented lists of several thousand subscribers. We need a generator that produces thousands of guaranteed-unique alphanumeric codes on demand, following a configurable pattern such as prefix, length, and character set.

Beyond raw generation, the tool must let us set an expiration date for each batch and a maximum number of times a code can be redeemed, whether a single use per code or a shared limit across the whole batch. We would also like to attach a discount value or type to a batch so the same interface can serve different campaigns. Once a batch is ready, we need to export the full list of codes into a file we can plug directly into our mailing service, so every subscriber receives a distinct code rather than one shared coupon.

A simple admin panel or a script with a clear interface both work, as long as it stays reliable and fast with tens of thousands of codes and is safe against accidental duplicates. Please describe your relevant experience and propose an approach.

Key requirements:
— guaranteed uniqueness across batches, not just within one
— configurable expiration date and usage limit per code or per batch
— export to a file format ready for a mailing campaign upload
— clean, documented code we can hand off to our team afterward