KotlinConf 2026 — Day 1 Impressions

KotlinConf 2026 opened today at the ICM, Internationales Congress Center Messe München. Day one ran the full range, from low-level coroutine internals to the shape of where the language is going. From Compose rendering optimisations you can apply next week to a look inside how Google rebuilt the search backend on Kotlin coroutines.

Here are the highlights of the talks I managed to catch.

Run, Kotlin, Run

Marc Reichelt

A lightning talk... that did exactly what it says on the tin. Move fast, cover ground, and leave you slightly energised.

Marc ran through the full spectrum of places Kotlin can execute today. JVM, native, JavaScript, WebAssembly.

The WASM story in particular is a worthy mention from this session. Kotlin/Wasm has matured considerably and the pitch of "one language, every runtime" is getting harder to dismiss as fluffy aspiration. I recall WASM based talks during KotlinConf 2025, and this particular talk made it feel less like a roadmap item and more like the present tense.

Opinionated Ktor Services

Simon Vergauwen

In my naive opinion, Ktor's unopinionated nature is both its appeal and its trap. The framework gives you the pieces but does not tell you how to assemble them. Simon's talk was a useful corrective, a practitioner's view of where the decisions actually land when you build real services with it.

A lot covered here, and the early morning caffeine was beginning to desert me ☕

Dependency injection approaches, code organisation, third-party SDK integration, testing strategy, and automatic API documentation generation. None of it is rocket science, but having someone work through the trade-offs out loud is its own brand of utility.

Ktor projects tend to develop opinions anyway. Better to develop them deliberately.

Ktor Documentation