Moving my serverless project to Ruby on Rails

I have a small side project: digital gift cards for hackers. It uses Shopify for all the store-related stuff: frontend, payments, refunds, reports, etc. But unlike regular digital products (ebooks, videos) I wanted each card that the user purchases from the store to be unique. So I made a script that generate personalized images and ran it manually for every order. The next logical step was automating this process. I started with serverless AWS Lambda. At the time it was a hot new tech and I wa...