When I joined ING, I was new to payments. I quickly learned that payments is a complex beast. Payments are in a lot of cases is based on “old” technologies, since it’s usually one of the oldest service the bank runs. Most banks still run a considerable amount of COBOL code. That by itself poses a set of unique problems, and banks are moving over to modern Java technologies.

I was hired to start the reactive systems car, and quickly shift it into the fifth gear. Being an experience developer and architect with a great team is what really drove me for the past two years. We POC’d a number of reactive technologies and programming languages, to ultimately and up with Akka and Java.

Then we really started on our reactive journey : The initial design with took a month, the scoped target product, the actual development and at the end, the delivery and putting it in production. We had a few setbacks, messed things up, had success stories, and had a lot of lessons on implementing our reactive, scalable payment engine.

I want to share our story with you, and tell your how we did it, and delivered a modern, scalable, resilient system in a traditional world.