Scala Central #21

13/02/2019  

We held our first Scala Central of 2019 at the Expedia Group/Hotels.com offices in Angel. This was our first time hosting at Expedia Group/Hotels.com and they were brilliant hosts.

After a small break before the new year it was great to see so many of you there, the room was full and it was brilliant to catch up with everyone after the holidays.

We had two talks this time from Greg Dorrell and Leszek Sliwko.

First up was Greg who took us through the different “effect types” and when and why they should be used. Greg’s talk followed with some great questions on the members own experiences and advice. It was great to have Greg involved once again as he was one of our first ever Scala Central speakers back in 2017!

Leszek followed with his talk on his experience of release/build processes and how this was set up in his team. His talk was not only relatable to Scala Developers, but could also be applicable for those working with other technologies too. Again, Leszek also attracted quite a lot of questions surrounding his choices of tools and techniques.

For those of you who couldn’t make it or would like to recap, the videos and talk details are below;

Greg Dorrell - Effect Types: What? Why? Which one?



In the last couple of years, a number of new “effect types” have been created. What is an effect type? When and why should you use them? Also, there’s a few of them, so which one should you use?

This talk will compare them to Futures and give motivation for using them. We’ll take a look at the different options; namely Cats Effect’s IO, Scalaz ZIO’s IO, and Monix’s Task.

Leszek Sliwko - Drone Delivery Queue


The presentation is about release/build process we setup in my team. The novelty here was to integrate the images building as a result of a story (i.e. not the code changes). Then the images are moved through environments – such a process guarantees the release on prod is exactly the same system as that which has been seen and approved by business.

You can also find the presentation here.

Thanks again to Greg, Leszek and the team at Expedia Group/Hotels.com for being fantastic hosts.

We will keep you posted on details for the next event, you can also keep up to date via the meetup page so if you’re looking to get involved by speaking or hosting it would be great to hear from you.

We’d really like Scala Central to be the best experience for everyone, so we also welcome any suggestions on how we can improve.

I hope you enjoyed the videos and look forward to seeing you at the next meetup.

See you soon!

Alice and the Scala Central team