Large Companies Are Switching to Kotlin: The Main Trend of 2025

Large Companies Are Switching to Kotlin: The Main Trend of 2025

2025 has become a turning point for the JVM ecosystem. If previously Kotlin was perceived exclusively as a "language for Android," now it is confidently gaining ground in corporate development, backend, and even cross-platform projects. Major players — from banks to tech giants — are massively migrating to Kotlin, and this is no longer just an experiment, but a deliberate business strategy.

Why is Kotlin Defeating Java?

The main factor is development productivity. Kotlin offers concise syntax, null-safety, and powerful functional capabilities that allow reducing code volume by 30–40% compared to Java. For large projects, this means reduced development time and fewer bugs.

The second reason is compatibility. Kotlin fully integrates with existing Java codebases, allowing companies to migrate gradually without rewriting millions of lines of code at once. The third is the growing ecosystem: Kotlin Multiplatform already allows using one codebase for Android, iOS, web, and desktop.

Migration Cases: Who Has Already Switched?

• Google — internal services and most new Android projects are written in Kotlin. In 2025, the company announced that 90% of new repositories are created exclusively in Kotlin.
• Amazon Web Services — actively uses Kotlin for writing SDKs and backend tools. Several key services migrated from Java to Kotlin, reducing error rates by 25%.
• JetBrains — the language's developers themselves migrated their core products (IntelliJ IDEA, TeamCity) to Kotlin, confirming its maturity.
• Sberbank — the Russian fintech giant announced in 2025 a full transition to Kotlin for new microservices. The team noted accelerated code reviews and simplified legacy maintenance.
• Uber — uses Kotlin for backend microservices and parts of the mobile client. The migration allowed reducing memory consumption by 15%.

Kotlin is Not Just for Android

It is a mistake to think that Kotlin only lives in mobile development. In 2025, the language has become a standard for:

• Backend services (Ktor, Spring Boot with Kotlin);
• Cross-platform mobile applications (Kotlin Multiplatform Mobile);
• Data Science (Kotlin for Data Science, KotlinDL library);
• Scripts and automation (Kotlin Script).

What Does This Mean for Developers?

The job market reacts instantly. According to HeadHunter and Glassdoor, the number of job vacancies requiring Kotlin grew by 60% in the first half of 2025. The average salary for a Kotlin developer in Russia exceeded 300,000 rubles, and on the international market — $130,000 per year.

For those who already know Java, switching to Kotlin takes only 2–3 weeks of active study. Companies are actively funding retraining for their teams, understanding the long-term benefits.

Forecast for the End of 2025

Analysts expect that by the end of the year, Kotlin's share in the corporate Java ecosystem will reach 35–40%. Moreover, Kotlin Multiplatform could become the de facto standard for