Why Scala?


Recently we started a new project and I’m happy to say we had quite a lot of freedom to choose the tech stack we wanted to implemented it.

Technically the project did not seem too difficult, basically just aggregating data from few different web service api:s. So it looked like a good chance to take a small chance and try something new. We decided to go with Scala and Play Framework and here is why:

Reactive Model

I had previously done some smaller project using node.js and event driven programming. I definitely think that “reactive” is the way to go and makes sense to learn to do it properly. The thing I was missing was a proper type system which leads to…

Static Typing

Scala’s type system is extremely powerful and type inference allows some compact and concise code. Read more here:


After (too ) many years of mostly Java development it was definitely time for something more powerful. Scala is pretty much as functional as a language can be. Some purist may argue that it’s not purely functional like Haskell, but in the real world situations Scala is as functional as they come.

Specifically Pattern Matching deserves to be mentioned as one of my favourite features.If you manage to specify most of your data model in case classes, life gets a lot easier.

Cake Pattern

Cake pattern is seems to be the go-to way of wiring Scala apps together. It basically allows you to do modular design and dependency injection without using any library. It does include a bit of boilerplate, but I think that the advantages of using statically typed, compile time checked dependency injection is better than using any separate library even with the price of a little bit of boilerplate. Read more about cake pattern here:

Java Interoperability

If Java has one strength, it’s the plenitude of well tested libraries. Using Java lib’s is trivially easy from Scala.


Scala recently turned 10 years old and the language is definitely mature enough. It still evolves, but latest stable releases are worthy of their name and stable.

Play Framework has reach version 2.3.7 and accompanying Activator makes starting projects very easy. Activator has pretty decent template mechanism and you got bunch of templates to choose from when you start a new project.

Sbt the Scala Build Tool has evolved like Scala. It’s regularly updated and has a working plugin system. It comes with a nice REPL. It might not look fancy, but it get’s the job done.

When it comes to IDE:s you got basically two fine choices: Eclipse based Scala IDE and IntelliJ. I personally found IntelliJ:s scala & play plugin to work better and eventually settled on that. The only downside is that play plugin requires the registered (paid) version.


Scala compiles to java bytecode so the performance is just as good. Static typing allows the compiler to optimize better. Just have a quick look at these benchmarks: http://benchmarksgame.alioth.debian.org/u32/compare.php?lang=scala&lang2=clojure
I chose to compare Scala to another modern jvm language with dynamic typing. Of course this is just a little sample, but Scala is across the board faster. It good to keep in mind that usually performance should be one of the last criterias when selecting the language, but it’s nice to know that when push comes to shove, Scala will deliver. There is a reason why internet giants like Twitter and LinkedIn chose Scala.


There you have, our reasoning for choosing Scala. After about 4 months into the project it still looks like a good choice. Don’t get me wrong, it has not been a walk in the park and we’ve had some difficulties and problems, but that’s the topic of an upcoming post.

Posted on 21/12/2014, in Scala, Software and tagged . Bookmark the permalink. Leave a comment.

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