Senior Compiler Developer (Kotlin Compiler - Core)

Senior Technical Product Manager (IntelliJ Kotlin Plugin)

JetBrains

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.

Senior Research Engineer (Agentic Behavior)

JetBrains

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.

Android Engineer - Engagement Mission

Sumup

About the team: The SuperApp & Web squad sits within the Engagement Mission under SumUp's Run & Grow tribe, and we're responsible for one of the most strategically important surfaces in SumUp's product ecosystem,  the merchant app home screen. Our mission is simple but ambitious: make every SumUp merchant feel empowered, informed, and engaged every time they open the app. We own the home screen, tools section, and profile & settings across iOS, Android, and Web,  and we build with four core objectives in mind: * Activate merchants so they start using SumUp products as early as possible, through a first-class onboarding and first-time user experience * Cross-sell & upsell SumUp products to the right merchants at the right time, via smart promotional components * Surface insights that help merchants manage and grow their businesses through home screen widgets * Enable navigation to the most relevant screens of the app. The squad is cross-functional and collaborative, made up of iOS, Android, and full-stack engineers, a senior backend engineer, a senior product manager, a senior designer, and an engineering manager. You'll be paired with a senior Android engineer who will support your onboarding and growth, giving you the space to develop your skills while contributing meaningfully from day one.    What you’ll do: * Build and maintain features of the Android SuperApp home screen, including the first-time user experience, home screen widgets, quick actions, customization, tools section, profile & settings, and promotional channels, with guidance from your senior peers * Contribute to the Personas initiative, helping build a tailored and customizable home screen experience that reduces friction and surfaces relevant data for each merchant * Support codebase modularization and refactoring efforts, learning how to write scalable, maintainable code in a real-world production environment * Participate in the definition and refinement of team initiatives, asking good questions, sharing ideas, and growing your technical judgment over time * Take part in code reviews as both a contributor and a reviewer, building good habits around clean code and engineering best practices * Write clear technical documentation and gradually build confidence communicating with stakeholders across product, design, and engineering * Embrace a culture of curiosity, ownership, and continuous learning, this is a place where growth is expected and supported   You’ll be great for this role if you: * Are proficient in Kotlin and have hands-on experience with Jetpack Compose for building Android UIs * Have a working knowledge of MVVM, MVP, or similar architectural patterns and understand the value of clean, well-structured code * Experience working with large monorepos and building different flavors of Android apps * Are comfortable working in evolving codebases and are eager to learn how to navigate complexity and contribute to refactoring efforts * Have a genuine UI/UX sensibility,you care about building experiences that feel right, not just code that compiles * Are a team player who has worked alongside engineers, product managers, and designers in a cross-functional environment * Bring curiosity, adaptability, and a growth mindset, you ask questions, take initiative, and aren't afraid to say "I don't know yet, but I'll find out" * Can communicate your ideas clearly in writing and are willing to build your technical documentation skills over time Nice to have:  * Experience with Firebase, Optimizely, or API design  * Experience with Design Systems, motion, or accessibility on Android Why you should join SumUp: 🌍 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup 🧑‍🔬 We take learning and experimentation seriously with Hack Days every second Friday, and entire global Hack Weeks. 🌈 Commitment to Diversity and Inclusion: Be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced 📚 A dedicated annual L&D budget of €2,000 for attending conferences and/or advancing your career through further education 🚀 Enrolment onto our VSOP program: You will own a stake in SumUp’s future success 💶 A corporate pension scheme where we match up to 20% of your contributions 🔄 30 Days Sabbatical: Enjoy the unique opportunity to take a well-deserved break with our 30 days sabbatical benefit after completing 3 years of employment with SumUp 🔗 Referral Bonus: Earn additional rewards by referring talented individuals to join the SumUp team 🚵🏾‍♂️ Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance, relocation assistance, subsidised office lunches   SumUp is an Equal Employment Opportunity employer that proudly pursues and hires a diverse workforce. SumUp does not make hiring or employment decisions on the basis of race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by Company policy. SumUp also strives for a healthy and safe workplace and strictly prohibits harassment of any kind. About us: Be empowered to do more that matters. At SumUp, we're on a mission to empower small businesses across the globe by providing simple and affordable tools that allow them to thrive. Today, over 4 million businesses in 36 markets rely on SumUp as their financial partner to manage payments, finance and customer relationships. Our commitment to small businesses is reflected in our diverse team of over 3,000 SumUppers from over 90 nationalities, united by global collaboration and an innovative mindset. Our core values lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster inclusivity and a continuous learning culture, providing a safe space for personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify.  SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited. Explore career opportunities with us and join a team driven by collaboration, innovation, and a shared vision of creating a world where everyone can build a thriving business. Discover more about our vibrant and inclusive work culture and how we work on our careers website, and follow our journey on LinkedIn and Instagram. Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.