Software Developer for ThinkRail (Innovation Hub)

Location: Belgrade, Serbia; Berlin, Germany; Limassol, Cyprus; Munich, Germany; Paphos, Cyprus; Prague, Czech Republic; Remote, Germany; Warsaw, Poland; Yerevan, Armenia

Department: Bonsai

At JetBrains, code is our passion. Ever since we started, back in 2000, we have strived to make the strongest, most effective developer tools on earth. By automating routine checks and corrections, our tools speed up production, freeing developers to grow, discover, and create.

ThinkRail is an innovative project within JetBrains' Innovation Hub. Its aim is to develop a declarative programming language tailored to AI-spec-driven development. Our goal is to build an infrastructure that enables the efficient creation of complex systems with AI, while maintaining the trust of users and flexibility in the results.

Thinkrail is now open source and in alpha, and we’re entering the next stage of the product’s development: initial market penetration. We’re focused on bringing it into real-world projects and turning it into a robust, production-ready system. To help us get there, we’re looking for a software developer to join the team. You’d be joining at an early stage, with plenty of opportunity to influence the product, tooling, and architecture as they continue to evolve.

This will be an exciting opportunity if you:

• Want to create something new.
• Care about building trust in AI.
• Love programming languages.

In this role, you will:

• Build and evolve VS Code and IntelliJ IDEA plugins for ThinkRail.
• Develop our language server, including analysis, completion, diagnostics, and verification.
• Improve the evaluator that turns specs into code and catches spec and code drift.
• Integrate ThinkRail with AI agent frameworks (e.g. Koog, LangGraph, and Spring AI) and protocols like MCP and ACP.

We will be happy to have you on our team if you:

• Can work effectively in a distributed team.
• Have strong collaboration skills, are open to diverse perspectives, and support your ideas with sound reasoning.
• Possess exceptional problem-solving skills and initiative.

We would be especially thrilled if you:

• Are experienced with developer tools, DSLs, or static analysis.
• Have hands-on experience working with LSP or editor plugins (for VS Code, IntelliJ IDEA, or similar).
• Are interested in or experienced with AI agents and how they’re orchestrated in real systems.

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