Scala Field Report

Hi all,

In this meetup two of our members, Jos Dirksen (https://www.meetup.com/brabant-scala/members/182468952/) and Jan Ouwens (https://www.meetup.com/brabant-scala/members/185208934/), will share some interesting topics from their daily work at Equens and Rabobank respectively. Both topics will cover type-classes.

Program:

18:00 - Entree
18:30 - Food
19:00 - Two patterns that make the life of a Scala engineer a lot simpler, by Jos Dirksen
19:45 - Short break
20:00 - A DSL for financial calculations, by Jan Ouwens
21:00 - Chat & drinks

The meetup will be hosted by iHomer (http://www.ihomer.nl/) at their new location in Dongen.

Hope to see you there!

Brabant Scala
Hugo

---

Two patterns that make the life of a Scala engineer a lot simpler

In this short talk we'll look at two patterns we currently use a lot at Equens. The interpreter pattern, implemented using Free Monads, which allows you to abstractly specify control flow between pure functions, and separately define an implementations, and the well known type-class pattern, which allows us to extend the functionality of an object, without explicitly implementing traits.

Jos is a Devops / Scala engineer currently working at Equens. He has been working as a software guy for over a decade, mostly with Java, but made the switch to Scala a couple of years ago. At his current project he is creating a buzzword compliant microservices architecture using Docker, AWS, Consul, Cassandra, Scala, Akka, Spray and a little bit of Go.

---

A DSL for financial calculations

For Rabobank's mortgage calculations, we have built a DSL within Scala that helps us express these complex calculations in a way that is both fully typesafe, and easy to read, not just for developers but for business analysts as well. In this talk, I will explain the concepts of the DSL, how we implemented them, and why we implemented them the way we did.

Jan Ouwens is a Scala developer at Ordina since spring 2015, but has already been tinkering with Scala and Akka for the past 5 years. He's worked on a wide variety of projects over the years in the fields of service management, electron microscopes, banking, and the operation of trains, and he's worked with an equally wide variety of languages such as Java, C#, Jess/Clips, and even VB script. Jan is also the creator of EqualsVerifier.