Entraspan has written numerous e-Commerce systems in what we would consider large scale.

A e-Commerce business may only have a small number of items, which would allow for a very large variety of platforms to run on.

Somewhere between 5-10 K items things change, where caching becomes a bigger factor to provide quick response times, and tighter integration with suppliers becomes critical to provide good customer service.

Entraspan provides solutions for sites containing 5 K to 100's of thousands of products with completely integrated purchasing, inventory, and fulfillment.