Software Developer ( Fleet_Compose API & UI Toolkit)

At JetBrains, we aim to make developers as productive as they can be. We believe that productivity is not just about writing code quickly — it's about staying in the flow, feeling in control, and your tools not getting in your way. A key part of that experience is a user interface that is responsive, intuitive, and deeply integrated with the developer’s workflows.

Fleet is our next-generation development platform, built to change how developers interact with JetBrains tools. It was designed to facilitate a well-integrated, high-performance user experience across devices and platforms, including desktop, web, and mobile. It was constructed from the ground up to leverage concurrency, treat distributed use-cases as first-class citizens, and enable a state-of-the-art development experience based on Kotlin and Compose.

We’re currently looking to strengthen the UI Platform team across several focus areas. Whether you're passionate about UI frameworks, component libraries, platform integration, or performance optimization, there’s an opportunity to make a big impact.

Your responsibilities may include:

• Developing the internal UI toolkit that powers Fleet into a consistent, maintainable, and well-designed library aligned with the Compose style guide. Eventually, this may include open-sourcing it and making it available as a dedicated library.

• Designing and maintaining reusable low-level UI primitives and APIs where the existing Compose APIs are lacking, with a focus on clarity, coherence, and long-term maintainability.

• Collaborating with other teams to align our UI stack with Compose Multiplatform (CMP), both within JetBrains and with the Jetpack Compose team at Google, contributing to upstream efforts and helping converge divergent forks.

• Improving platform integration to ensure that Fleet feels native and responsive across all relevant platforms.

• Analyzing and optimizing the performance of the Fleet UI Platform within our products to ensure consistently high frame rates on all platforms.

• Helping extend and refine the usage of Compose within product code, cleaning up deprecated patterns and improving structural consistency.

• Sharing knowledge among all team members and helping ensure architectural continuity and technical resilience.

  
  

What we’re looking for:

• Solid experience with reactive-declarative UI programming. Experience with Compose (Jetpack, Desktop, or Multiplatform) is a strong advantage.

• Familiarity with or interest in building UI frameworks, including how reactive/declarative runtimes work under the hood.

• Experience with API design and maintenance, ideally related to UI frameworks, component libraries, or platform integration.

• A focus on code quality, maintainability, and thoughtful software architecture.

• A passion for refining the user experience and finding alignment between UX design and its implementation.

• A willingness to collaborate, share knowledge, align on a common style, and make contributions across a wide range of layers and systems.

• The readiness to dog-food and develop from different platforms.

  
  

This position is flexible in scope, and we’re open to adapting the role to your experience and interests. Whether you're excited by deep internals, the developer experience, cross-platform consistency, or hands-on UI development, we’d love to hear from you.

Jobs you might like

ML Researcher (Kotlin)

Senior Software Developer (AI Enterprise)

Senior Software Developer (IDE Services Core)

QA Engineer (IntelliJ Kotlin Plugin)

Staff Kotlin Developer (Generation Algorithms and Experiments)