Informal get-together of Kotlin developers in Berlin

Welcome to our yet another informal get-together. This time we are packed with 3 talks and quite officially we will be hearing about:

1. Coroutines vs. ReactiveX: Handling errors by Milos Marinkovic

Imagine you're writing asynchronous code.

• Are you using callbacks? (no)
• Are you using Futures? Reactive streams?
• Are you using async features of your language of choice?

Whatever the answers are, you want to handle problems correctly. Let's compare Coroutines and ReactiveX in this regard and see some of the most common use-cases when writing asynchronous code with Coroutines.

2. The power of types by Danny Preussler

From Assembler, over Fortran and C to modern Kotlin, we came a long way and improved the way we can express our thoughts in code.

One thing that happened during this journey is that languages allow us to use types for our problem domain, independent of the underlying computer architecture. Types became a powerful tool.

Types improve readability which probably is the most important aspect of programming! But types also prevent you from making mistakes at compile time. This is why Kotlin translated the null problem into the type system.

We can use these powers in our daily lives. We can write better code by avoiding “primitive obsession”. I’ll show you how!

3. Composable Error Handling by Stojan Anastasov

As Software Developers we try solve complex problems. To solve them we first split them into smaller, simpler ones and write code that fulfills the simpler requirement. We combine those pieces of code to solve the larger problem. Ideally we aim to write 0 glue code to compose the code that solves the small problems into a program that solves the big one.

In this talk we will take the example of validation. We will explore how different validation strategies work in terms of error reporting, composition and ease of use. Along the way we will create a simple data type and a few utility functions, that will lead us to nice home-grown solution, that works. Finally we move to a battle proven library.