A full stack side project webapp all in Kotlin (KotlinConf 2025)

It's happened to all of us – an idea strikes for a side project and you want to build a quick webapp, but then you remember the state of webdev is still a bit of a mess in 2025. Sure you could pick up one of those "all-in-one" frameworks, but they're so heavy and complicated. And even if that worked, you'd still need something on the frontend so you start looking at the the weird world of frontend frameworks or (gasp!) writing raw HTML/CSS/JavaScript.
But it doesn't have to be that hard! I'm here to present a straightforward stack that gets you a full stack webapp up and running fast, using the one language we all know and love – Kotlin. Database manipulation, async services, and a high fidelity UI, all accessed and built with Kotlin. And yes, you read that right – you can have a great UI without having to write a single line of CSS, HTML, or JavaScript.
I'll show you a path for building a basic webapp on top of a simple database (Postgres), performing basic CRUD operations on that database (Kotlin Exposed), building business logic via async services (Kotlin Coroutines), and constructing a high-fidelity UI to bring it all together (Vaadin on Kotlin). By the end of the talk we'll have a fully functional webapp that is entirely built on Kotlin.
And let's not forget, we're not building a by-the-book, very serious webapp, just something we're doing on the side for fun. So forget about tests and forget about perfect architecture – let's have some fun, learn a few things along the way, and get this thing running!