Programming in Haskell -- payme, an example fintech application

Time for a new project! I want to explore the "boring" parts of building a real world app in Haskell: things like logging, metrics, error handling, deployment, etc. I also want to look at how to structure an application using an effects library. To do this I'm going to start a new project and try to solve these things to the same level I'd use for production code.
The project will be a little payment app, with hopefully enough complexity to make it realistic but without so much that it takes forever to create. In this episode I'll outline the basic functionality and start putting some core pieces in place.