[leviathant]

Hmm. The one thing that stuck out to me was "millions of promotions" - how are you quantifying that?

Are you developing/looking to develop this yourself internally as a retailer, or are you building this out on behalf of a retailer? Some of the other bits you've mentioned certainly sound complex (although this might be how you've approached these combinations of options and products), but not outside the realm of a Spree/Solidus or Workarea style implementation.

[crisscrosscrash]

I'm developing internally as a retailer. Having millions of coupon codes or gift cards is important for sales and doing deals with partners or sites like Groupon. Then, with many items across many categories, as well as tons of add-on options, application and stacking of multiple rules needs to be powerful, but it seems like Spree now provides all the tools to make that manageable.