Survey: Which Kotlin Frameworks Are Actually Used in Production

Survey: Which Kotlin Frameworks Are Used in Production

The Kotlin ecosystem is evolving rapidly: the language has long been not limited to Android development, actively conquering server, web, and even frontend spheres. But which Kotlin frameworks actually work in production environments, and not just in pet projects? A recent survey of 500+ developers at the KotlinConf conference and in professional communities provided a clear answer. We break down the top 5 tools chosen for production.

Leaders of the Race: Spring Boot vs Ktor

The undisputed leader remains Spring Boot (42% of respondents). Despite being a framework from the Java world, its full compatibility with Kotlin, convention over configuration, and huge community make it the #1 choice for enterprise applications. Second place with an impressive 31% was taken by Ktor — a native Kotlin framework from JetBrains. It is chosen for:

• Asynchrony "out of the box" on coroutines;
• Minimalism (no heavy servlet container);
• Simple DSL for routing and middleware.

Interestingly, 18% of respondents use both frameworks simultaneously: Spring Boot for complex business logic and monoliths, and Ktor for microservices and API Gateway.

Dark Horses: KVision and http4k

Third place with 9% was taken by KVision — a framework for full-stack development. It allows writing frontend in Kotlin, compiling it to JavaScript. An unexpected rise was shown by http4k (6%): its functional approach and lightweight nature (only 8 KB) are valued by teams practicing serverless and AWS Lambda.

The remaining 3% went to experimental frameworks: Javalin, Jooby, and Vert.x. Notably, 78% of respondents use Kotlin Multiplatform to share logic between server and client.

Key Survey Trends

• Coroutines — a must have: 94% of Kotlin projects use coroutines for asynchrony, even in Spring Boot (via the spring-webflux module).
• Serialization is changing: Kotlinx.serialisation has overtaken Jackson in new projects (55% vs 38%).
• Microservices on the rise: 62% of production Kotlin projects use a microservice architecture, where Ktor plays a key role.
• Testing via DSL: 70% of developers use Kotest (a Kotlin testing framework) instead of JUnit.

Tips for Choosing a Framework

If you are deciding on a new project, focus on the tasks:

• Enterprise / Java developer team — choose Spring Boot + Spring WebFlux;
• High-load API / real-time — Ktor with Netty or ktor-server-cio;
• Full-stack in one language — KVision or Kotlin/JS with React wrappers;
• Serverless / FaaS — http4k or Ktor with ktor-server-lambda.

The survey confirmed: Kotlin has ceased to be "just another JVM language." It is forming its own