I think you are right on - staying in the same stack was, at the time this blog post was written (Feb 2015) a more pressing need, which pushed us to try and ben

I think you are right on - staying in the same stack was, at the time this blog post was written (Feb 2015) a more pressing need, which pushed us to try and bend the ActiveRecord pattern to be used for payments. As our team grew and we no longer had the strong requirement of staying in the same stack, we did indeed started to break out the payments code into a micro-service, written in java (java8, dropwizard, jooq, mysql).