At JetBrains, code is our passion. Ever since we started, back in 2000, we've been striving to make the strongest, most effective

developer tools on earth. Today, AI-powered coding agents are becoming a core part of how developers write Kotlin – and we want to

make sure they write it well.

The Kotlin AI Value Stream team is responsible for how AI agents understand, generate, and improve Kotlin code across all

platforms: Android, Kotlin Multiplatform, server-side, web, desktop, and others. We build the evaluation infrastructure, error

analysis tools, and post-training pipelines that measure and improve agent behavior on real Kotlin developer tasks.

As a Research Engineer on this team, you'll own the end-to-end loop: Analyze how agents fail on Kotlin → build evals that capture

those failures → research and implement methods to fix them → measure the improvement. Your work will directly shape how millions

of developers experience Kotlin through AI coding agents.

AS PART OF OUR TEAM, YOU WILL:

Build tools for agentic error analysis

Design and implement tooling to systematically capture, classify, and analyse errors that AI coding agents make when generating

Kotlin code.

Build observability pipelines over agentic traces – mining patterns from agent sessions in JetBrains IDEs, Junie, Claude Code,

Cursor, and other coding agents.

Build evaluation pipelines

Design, implement, and maintain evaluation pipelines that measure Kotlin code generation quality across dimensions, including

correctness, idiomaticity, build success, framework usage, and test coverage.

Build simulation environments where coding agents can be measured on realistic Kotlin developer tasks – from greenfield KMP

projects and Gradle dependency management to migrating Spring applications from Java to Kotlin.

Own evaluation infrastructure: metrics, experiment tracking, automated regression checks, and reproducible benchmarking.

Research methods for improving agent and model behavior on Kotlin

Experiment with post-training techniques (SFT, DPO, GRPO) to improve how models handle Kotlin-specific patterns, idioms, and

frameworks.

Investigate context engineering approaches: CLAUDE.md/AGENTS.md files, compiler-as-verifier feedback loops, Kotlin LSP

integration, and MCP-based tooling.

Run experiments to measure impact: A/B comparisons, benchmark suites, and before/after analyses on real codebases.
Collaborate with model providers (Anthropic, OpenAI, and Google) to translate Kotlin-specific findings into model improvements.

Build public Kotlin benchmarks

Design and build open-source benchmarks that measure AI coding agent performance on Kotlin tasks and eventually become the

standard reference for the ecosystem.

Create task datasets covering the breadth of Kotlin usage: the server side (Spring, Ktor), multiplatform projects (KMP), build

systems (Gradle), Android, library development, and others.

Include both mined real-world tasks and carefully designed synthetic tasks that test specific Kotlin capabilities.
Maintain and evolve benchmarks as models improve, ensuring they remain challenging, relevant, and contamination-resistant.

WE'LL BE HAPPY TO HAVE YOU ON BOARD IF YOU HAVE:

Hands-on experience building evaluation or analysis pipelines for LLMs or AI coding agents in a research or production setting.
Strong Python engineering skills (at least three years), with the ability to write clean, maintainable code in data-heavy and

ML-adjacent codebases.

Experience with data analysis at scale: querying large datasets (SQL/Athena), building data pipelines, and performing

statistical analysis of experimental results.

The ability to own projects end to end – from identifying a problem in agent traces to designing an eval, running experiments,

and shipping a fix.

A product-aware mindset: You care about how agents are actually used by developers and can translate real failure modes into

evaluation and training work.

Familiarity with Kotlin or a strong willingness to develop deep Kotlin expertise (you'll be living in Kotlin codebases daily).

OUR IDEAL CANDIDATE WOULD ALSO HAVE EXPERIENCE WITH:

Post-training LLMs: SFT, RLHF, DPO, GRPO – either hands-on training or designing the data and reward pipelines that feed into

training.

Modern deep learning frameworks (PyTorch) and LLM training stacks (TRL, verl, Megatron, or similar).
AI agent development: tool-using agents, multi-step coding workflows, agentic frameworks.
Evaluation frameworks and tools: Inspect AI, Promptfoo, LM-evaluation-harness, or custom eval pipelines.
Experiment tracking and observability: Weights & Biases, MLflow, Langfuse, or similar.
The Kotlin ecosystem: Android, Gradle, KMP, Spring, Ktor – with an understanding of the developer workflows that agents need to

support.

Contributing to or maintaining open-source projects, especially benchmarks or evaluation tools.

Don't check every box? That's okay – if you're excited about this work and bring strong fundamentals, we'd love to hear from you.

We're happy to talk and provide the training you need to grow into the role.

WHY JOIN JETBRAINS?

Strong base salary. We offer competitive pay that reflects your skills and experience.
Flexible work location. Enjoy the freedom to work from home or from the office.
Remote work. Spend up to 30 days per year working remotely from abroad.
Extra time off. More days to relax, recharge, and do the things you love.
Medical insurance allowance. Enjoy peace of mind for you and your family
Learning and development opportunities. Access to conferences, courses, and language classes.
Relocation support. We help make your move as smooth and stress-free as possible.
Language classes. Pick up the local language or sharpen your English skills.
Fuel your day. Enjoy a hot meal or receive a lunch allowance on workdays.
Mental health support. To help you feel your best, we provide easy access to professional mental health services.
Sports benefit. Enjoy an on-site gym or sports club stipend.
Internal events. Join company-wide celebrations and team gatherings.

Some benefits may vary depending on location.

#LI-KP1

We are an equal opportunity employer

We know great ideas can come from anyone, anywhere. That’s why we do our best to create an open and inclusive workplace – one that

welcomes everyone regardless of their background, identity, religion, age, accessibility needs, or orientation.

We process the data provided in your job application in accordance with the Recruitment Privacy Policy.

Role

Senior Research Engineer (Agentic Behavior)

Tags for this job

Kotlin Ecosystem

Similar Jobs

Senior Technical Product Manager (IntelliJ Kotlin Plugin)

JetBrains

Amsterdam•Posted: Jun 15•Deadline: Aug 16

At JetBrains, code is our passion. The Kotlin plugin for IntelliJ IDEA is where language meets experience — it's how hundreds of thousands of developers write, navigate, refactor, and understand Kotlin code every day. Being able to continuously improve it means understanding the language deeply, using the product daily, and deeply caring about Kotlin developers. We're looking for a Senior Technical Product Manager who will own the Kotlin-in-IDE experience end to end. This is a deeply hands-on role. You will experiment with Kotlin in IntelliJ based IDEs every day, maintain reference projects that double as regression canaries and demo showcases, build prototypes with AI coding agents, analyze users feedback and talk to users. You won't manage from slides — you'll manage from the editor. IN THIS ROLE, YOU WILL: * Own the product vision for the Kotlin plugin: fast, correct, and trustworthy IDE support that evolves with the language. * Use IntelliJ IDEA with the Kotlin plugin daily — dogfooding features, catching regressions, and validating the developer experience first-hand. * Maintain and develop reference Kotlin projects that serve as showcases for new features, material for conference demos, and a living test bed for DX quality. * Build prototypes and proofs-of-concept using AI coding agents to explore and validate new capabilities. * Own and continuously adapt the plugin roadmap across short-term release goals, mid-term initiatives, and longer-term Kotlin ecosystem related projects. * Align plugin planning with Kotlin compiler releases, IntelliJ IDEA release trains, and Android Studio constraints. * Make explicit trade-offs and say "no" when cost, risk, or maintenance burden outweighs user value. * Define problem statements, success criteria, and scope for features — then collaborate with engineers to validate and refine. * Represent core Kotlin personas — JVM backend developers, library authors, Android and Multiplatform teams — and prioritize recurring pain points: false positives, slow analysis, unreliable refactorings, onboarding pain points, AI agents integrations. * Run a consistent pipeline of monthly user interviews to ground decisions in real workflows. * Coordinate with Kotlin language team, Developer Advocates, framework partners, Marketing, and other JetBrains teams. * Create external visibility through what's-new posts, Kotlin User Groups meetup talks, and feature previews at events like KotlinConf, Spring I/O, Devoxx and others. WE'RE LOOKING FOR SOMEONE WHO: * Has professional software development experience in Java or Kotlin (this is a must). * Has 5+ years of experience in technical product management or a comparable role in a complex technical domain. * Is a hands-on product person who lives in the product, not someone who operates through reports and meetings alone. * Has experience with AI coding tools and agents, and curiosity about how they reshape developer workflows. * Can define clear roadmaps with problem statements, success criteria, and explicit trade-offs. * Has strong communication skills in English — written and spoken — for both technical peers and executive audiences. * Is ready to represent the product externally at conferences, in blog posts, and in community interactions. * Takes developer experience personally — not as an abstract metric, but as something they feel in their own daily workflow. WE'D BE ESPECIALLY THRILLED IF YOU: * Have experience developing IntelliJ plugins or working with the IntelliJ Platform SDK. * Have built or contributed to evaluation pipelines, benchmarks, or quality measurement systems. * Have given technical talks or published content aimed at developer audiences. WHY JOIN JETBRAINS? * Strong base salary. We offer competitive pay that reflects your skills and experience. * Flexible work location. Enjoy the freedom to work from home or from the office. * Remote work. Spend up to 30 days per year working remotely from abroad. * Extra time off. More days to relax, recharge, and do the things you love. * Medical insurance allowance. Enjoy peace of mind for you and your family * Learning and development opportunities. Access to conferences, courses, and language classes. * Relocation support. We help make your move as smooth and stress-free as possible. * Language classes. Pick up the local language or sharpen your English skills. * Fuel your day. Enjoy a hot meal or receive a lunch allowance on workdays. * Mental health support. To help you feel your best, we provide easy access to professional mental health services. * Sports benefit. Enjoy an on-site gym or sports club stipend. * Internal events. Join company-wide celebrations and team gatherings. *Some benefits may vary depending on location. #LI-KL1 We are an equal opportunity employer We know great ideas can come from anyone, anywhere. That’s why we do our best to create an open and inclusive workplace – one that welcomes everyone regardless of their background, identity, religion, age, accessibility needs, or orientation. We process the data provided in your job application in accordance with the Recruitment Privacy Policy.

Kotlin Ecosystem

Customer Success Engineer (Kotlin Multiplatform)

JetBrains

Amsterdam•Posted: Jun 15•Deadline: Aug 16

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. We’re looking for a Customer Success Engineer (CSE) to help engineering teams successfully adopt Kotlin Multiplatform (KMP) in real-world production environments. ROLE DESCRIPTION: This role focuses on supporting organizations throughout their Kotlin Multiplatform (KMP) adoption journey, from initial evaluation to successful production rollout, while also contributing to product improvements and the roadmap, with focus on KMP adoption, evaluation, feedback and advocacy. * Engage with organizations at various stages of KMP adoption within existing projects. * Support teams through migration, integration, and scaling of shared codebases. * Help teams overcome technical blockers and successfully move from experimentation to production use. * Proactively engage with prospective users who may benefit from KMP. * Understand customer use cases, technical constraints, and adoption challenges. * Provide practical guidance on feasibility, architecture decisions, and adoption strategies. * Gather structured feedback, insights, and pain points from customers. * Collaborate with product and engineering teams to influence the KMP roadmap and tooling improvements. EXAMPLE OF THE QUESTIONS YOU'LL HELP ORGANIZATIONS ANSWER: * What’s the safest way to migrate a large Android app to shared logic? * How much should we actually share? * Our iOS team struggles with Kotlin APIs and pushes back. How do we address this? * How do we organize the codebase for better cross-team collaboration? * We added KMP, but builds became painfully slow. How do we fix that? WHAT SUCCESS WILL LOOK LIKE: * Organizations successfully adopt and ship Kotlin Multiplatform in production. * Shared code usage expands over time across teams. * Adoption continues beyond the initial evaluation phase. * Tangible improvements are made to the KMP product and tooling, driven by user feedback. WE WILL BE HAPPY TO HAVE YOU ON OUR TEAM IF YOU HAVE: * Strong experience with Kotlin (Android or backend). * A solid understanding of mobile architectures across Android and iOS. * Excellent communication and stakeholder management skills, with the ability to engage, influence, and build trust with senior engineers, tech leads, and business stakeholders. * The ability to clearly explain complex technical concepts to diverse audiences, adapting depth and messaging as needed. * Experience leading customer conversations, facilitating discussions, and aligning cross-functional teams. * A proactive and empathetic approach to understanding customer needs, challenges, and goals. * The willingness to travel up to 25% of the time. NICE TO HAVE: * Hands-on experience with Kotlin Multiplatform. * Experience migrating or modernizing legacy and large-scale codebases. * A background in customer success, solutions architecture, or similar customer-facing roles. WHY JOIN JETBRAINS? * Strong base salary. We offer competitive pay that reflects your skills and experience. * Flexible work location. Enjoy the freedom to work from home or from the office. * Remote work. Spend up to 30 days per year working remotely from abroad. * Extra time off. More days to relax, recharge, and do the things you love. * Medical insurance allowance. Enjoy peace of mind for you and your family * Learning and development opportunities. Access to conferences, courses, and language classes. * Relocation support. We help make your move as smooth and stress-free as possible. * Language classes. Pick up the local language or sharpen your English skills. * Fuel your day. Enjoy a hot meal or receive a lunch allowance on workdays. * Mental health support. To help you feel your best, we provide easy access to professional mental health services. * Sports benefit. Enjoy an on-site gym or sports club stipend. * Internal events. Join company-wide celebrations and team gatherings. *Some benefits may vary depending on location. #LI-HYBRID #LI-REMOTE #LI-JP1 We are an equal opportunity employer We know great ideas can come from anyone, anywhere. That’s why we do our best to create an open and inclusive workplace – one that welcomes everyone regardless of their background, identity, religion, age, accessibility needs, or orientation. We process the data provided in your job application in accordance with the Recruitment Privacy Policy.

Kotlin Ecosystem

Staff/Senior AI Engineer, AI for Code

JetBrains

Amsterdam•Posted: Jun 15•Deadline: Aug 16

At JetBrains, we build developer tools used by millions of engineers. The AI for Code team works on the next generation of coding agents and agentic workflows: systems that can understand codebases, plan and execute multi-step tasks, collaborate with developers, and ship reliable results inside real development environments. We are looking for a Staff/Senior AI Engineer to join the team and support these efforts. This role is for someone who can take our internal coding models, such as Mellum2, as well as open-weight models, and turn them into production-ready coding agents for our users. You’ll work on model training and fine-tuning, context engineering, tool use, evaluation, feedback loops, and product integration. This is not research in isolation – you’ll build systems that are used by tens of thousands of developers. WHAT YOU’LL DO: * Build production-ready coding agents and agentic workflows for real developer tasks inside JetBrains products. * Turn promising model capabilities into dependable product behavior through prompt design, context construction, fine-tuning, instruction-tuning, or other post-training techniques where appropriate. * Design and improve the agent loop itself, including tool use, execution strategy, safeguards, and task completion quality. * Create evaluation suites and quality infrastructure for agent behavior, including online and offline evaluations, regression checks, failure analysis, and release criteria. * Build feedback loops from real usage, using logs, user signals, and edge cases to improve data, evaluations, and agent behavior. * Work with both hosted frontier APIs and self-hosted or open-weight models, making pragmatic decisions about where each model belongs based on capability, latency, reliability, privacy, and cost. * Collaborate closely with product managers, software engineers, ML engineers, and researchers to ship features end to end. * Help define the technical direction for future work, especially in ambiguous areas where we need strong judgment rather than a prewritten playbook. WHAT WE’RE LOOKING FOR: * Strong software engineering fundamentals and a track record of shipping complex systems to production. * Hands-on experience building LLM-powered products, coding agents, or other AI systems. * Experience improving model behavior through systematic iteration, whether via prompting, context engineering, fine-tuning, preference optimization, or broader post-training methods. * Practical experience with evaluation and benchmarking for LLM systems, including defining task-grounded success metrics and catching regressions. * Experience working from noisy real-world signals rather than only from clean benchmark datasets. * Good judgment about trade-offs between model quality, latency, reliability, privacy, and cost. * Confidence working with ambiguity and taking ownership of a direction over multiple iterations. * Strong communication skills and the ability to align engineering and product decisions. WHAT SUCCESS LOOKS LIKE IN THE FIRST YEAR: * You ship one or more agent capabilities that users can rely on for meaningful work, not just demos. * You establish better evaluation coverage and clearer release criteria for agent behavior. * You help the team build a repeatable loop from idea to shipped capability: prototype, evaluate, learn from usage, improve, and scale. WHY JOIN US? You’ll help define what practical, trustworthy AI for software development looks like in real products. You’ll work on challenging problems at the boundary of model capability and product reality, with the freedom to stay hands-on and the scope to influence how the next generation of JetBrains AI systems is built. And: * Strong base salary. We offer competitive pay that reflects your skills and experience. * Flexible work location. Enjoy the freedom to work from home or from the office. * Remote work. Spend up to 30 days per year working remotely from abroad. * Extra time off. More days to relax, recharge, and do the things you love. * Medical insurance allowance. Enjoy peace of mind for you and your family * Learning and development opportunities. Access to conferences, courses, and language classes. * Relocation support. We help make your move as smooth and stress-free as possible. * Language classes. Pick up the local language or sharpen your English skills. * Fuel your day. Enjoy a hot meal or receive a lunch allowance on workdays. * Mental health support. To help you feel your best, we provide easy access to professional mental health services. * Sports benefit. Enjoy an on-site gym or sports club stipend. * Internal events. Join company-wide celebrations and team gatherings. *Some benefits may vary depending on location. #LI-KP1 We are an equal opportunity employer We know great ideas can come from anyone, anywhere. That’s why we do our best to create an open and inclusive workplace – one that welcomes everyone regardless of their background, identity, religion, age, accessibility needs, or orientation. We process the data provided in your job application in accordance with the Recruitment Privacy Policy.

AI for Code