Today, I gave the presentation to my coworkers entitled "Puppies & Ecommerce as an Engine". The presentation is strongly coupled with my work on Piggybak, and includes a discussion of traditional ecommerce platforms versus a lightweight ecommerce approach through modularity (Rails Engine). It also provides some code examples as how this does work in Piggybak.
Below are a few more related articles to my work on Piggybak. Check them out!