Research Engineer for LLM Training and Performance

At JetBrains, we are passionate about code. Since our inception in 2000, we have dedicated ourselves to creating the most powerful and effective developer tools available. By automating routine checks and corrections, our tools accelerate production processes, allowing developers to innovate and create freely.We are seeking a Research Engineer to take owners…

Join JetBrains as a Staff Research Engineer specializing in pre-training technologies. In this pivotal role, you will lead groundbreaking research initiatives aimed at enhancing our AI capabilities. Collaborate with a talented team of engineers and researchers to innovate and implement cutting-edge solutions that push the boundaries of software development and AI integration.

At the forefront of modern electronic trading, technology plays a critical role. IMC is on the lookout for exceptionally motivated individuals to leverage quantitative research methodologies and hands-on experimentation within the technology utilized by exchanges, connectivity providers, and our proprietary systems. Your mission will be to devise innovative strategies that enable us to outperform competitors in the fiercely competitive realm of ultra-low-latency trading.As a Performance Engineer at IMC, you will be integral in analyzing, optimizing, and fine-tuning the interaction of our systems with exchange technologies. Collaborating with cross-functional teams, you will be charged with identifying performance enhancements throughout the trading stack. This position merges technical expertise with innovative problem-solving to strategically outmaneuver the competition in a highly demanding technical environment.

Join Reaktor's Award-Winning Tech Community as an AI Developer!At Reaktor, we are on the lookout for innovative AI Developers to enhance our team in Amsterdam. If you excel in utilizing advanced AI technologies, crafting applications powered by large language models (LLMs), and steering projects through the complete software development lifecycle, we want to hear from you! Immerse yourself in our collaborative, low-hierarchy environment where your insights and creativity can lead to significant outcomes.Role OverviewAs an AI Developer, you will be a key player in a wide range of AI-focused software development tasks, encompassing everything from front-end design to production deployment.Your Responsibilities:Crafting and executing end-to-end applications powered by LLMs, including backend architecture and user interfaces, while ensuring both scalability and maintainability.Integrating commercial and open-source LLMs (such as OpenAI, Anthropic, Meta Llama) into production systems, employing APIs or fine-tuning methods.Developing end-to-end retrieval-augmented generation (RAG) pipelines, incorporating embeddings, vector databases (e.g., PostgreSQL with pgvector, ChromaDB, Pinecone), and effective prompt engineering strategies.Creating evaluation pipelines for model performance benchmarking and safety assurance.Collaborating with diverse teams to develop AI applications that tackle complex business challenges.Engaging with clients' technological and business teams to identify appropriate solutions tailored to their requirements.Providing exceptional technical expertise to both clients and team members.Conducting other software development tasks, including architectural contributions, test automation, and debugging.Candidate ProfileWe seek a curious and proactive AI Developer who is adept in working with LLMs and is comfortable navigating both the backend and frontend aspects of applications. A solid understanding of infrastructure and the principles behind transformer-based models is essential.

About ClickHouseRanked in the prestigious 2025 Forbes Cloud 100 list, ClickHouse stands out as a pioneering and rapidly expanding private cloud enterprise. With an impressive client base of over 3,000 and a remarkable annual recurring revenue (ARR) growth exceeding 250% year-on-year, ClickHouse is at the forefront of real-time analytics, data warehousing, observability, and AI-driven workloads.The company’s ongoing success was recently reinforced by a substantial $400M Series D funding round. Within the last quarter, notable clients such as Capital One, Lovable, Decagon, Polymarket, and Airwallex have either adopted our platform or increased their existing usage. These companies join a renowned group of AI trailblazers and global giants including Meta, Cursor, Sony, and Tesla.Join us on our mission to revolutionize the way organizations interact with data. Embark on this exciting journey with us!About the TeamThe Cloud Performance Engineering team is tasked with developing the cloud-native ClickHouse Cloud Platform that is set to redefine the OLAP landscape. We are seeking outstanding performance engineers who possess a deep understanding of the performance thresholds of various distributed databases, alongside a knack for crafting tools that assess the performance and scalability of intricate systems. The ideal candidate will be a performance engineer specializing in distributed systems, equipped with robust experience in database benchmarking, test automation, system engineering, performance analysis, and capacity management. This role presents a unique chance to make a profound impact on our elastic, infinitely scalable, high-performance, serverless ClickHouse Cloud.Your Responsibilities:Conduct benchmarking of system performance and database performance analysis, focusing on capacity sizing and optimization.Diagnose and resolve application and server errors by analyzing logs and implementing appropriate triage measures.Propose configuration optimizations to address performance bottlenecks.Collaborate closely with the core development, cloud, and security teams to enhance ClickHouse Cloud’s performance.Initiate and lead Chaos Engineering projects across engineering teams, aligned with internal objectives.Create, implement, and oversee tools to systematically conduct chaos experiments and evaluate their effects.Delve into and cultivate a comprehensive understanding of large-scale distributed systems.Examine challenges in software resilience, operations, and delivery processes.Enhance our backend systems to incorporate Chaos Engineering methodologies.Monitor live systems and identify innovative ways to introduce disruptions.

Join our innovative team at Pinely as a Machine Learning Performance Engineer. We are on a mission to accelerate large-scale model training by optimizing our internal infrastructure and computing stack. In this pivotal role, you will engage with the entire training pipeline—from GPU kernels to system-wide throughput—utilizing profiling, CUDA-level tuning, and advanced distributed systems methodologies. Your contributions will be vital in minimizing training durations, enhancing iteration speeds, and maximizing computational efficiency.As a key member of our growing team, you will help cultivate deep technical expertise in ML training systems.Responsibilities:Enhance our model training pipeline to increase speed and reliability, facilitating quicker and more effective experimentation.Utilize GPU optimization techniques via tools like JAX, Triton, and low-level CUDA to elevate training performance and efficiency at scale.Diagnose and rectify performance bottlenecks throughout the ML pipeline—from data loading and preprocessing to CUDA kernels.Develop tools and expand our internal infrastructure to enable scalable, reproducible, and high-performance training workflows.Guide and mentor engineers and researchers in implementing performance best practices across the team.Assist in enhancing the team's capabilities in GPU and systems-level expertise, contributing to a culture of engineering excellence and rapid experimentation.Requirements:Proven experience optimizing neural network training in production or large-scale research environments, such as reducing training time, enhancing hardware utilization, or expediting feedback cycles for ML researchers.Extensive hands-on experience with ML frameworks like PyTorch or JAX.Practical experience training and optimizing deep learning architectures, including LSTM and Transformer-based models with various attention mechanisms.Familiarity with CUDA, Triton, or other low-level GPU technologies for performance tuning.Expertise in profiling and debugging training pipelines using tools like Nsight, cprofiler, CUDA, gdb, or torch profiler.Comprehension of distributed training concepts including data/model/tensor/sequence/pipeline/context parallelism and memory-compute trade-offs.A collaborative and proactive approach, coupled with strong communication skills and the ability to mentor team members effectively.Strong proficiency in Python for developing infrastructure-level tools, debugging training systems, and integrating with ML frameworks and profiling tools.What We Offer:Competitive salary and comprehensive social benefits.Attractive bonus structure; we are flexible in discussions regarding salary and employment conditions.Access to state-of-the-art hardware and software in production, alongside a highly skilled technical team.

At JetBrains, we are passionate about crafting exceptional developer tools. Since our inception in 2000, we have dedicated ourselves to creating the most effective and innovative solutions for developers around the globe. With the rise of AI-assisted technology, we are at the forefront of integrating these advancements into our integrated development environments (IDEs). Join our Agentic Models team as a Research Engineer, where you will play a pivotal role in developing multi-step coding agents capable of comprehending extensive codebases, strategizing modifications, utilizing tools, and engaging interactively with users. You will be responsible for designing models, training loops, and evaluation pipelines that drive these intelligent coding agents. Your work will involve merging supervised fine-tuning (SFT) techniques with reinforcement learning (RL) methodologies, coupled with product-oriented evaluations, leveraging our distributed GPU and MapReduce clusters to deploy models across JetBrains products.

At JetBrains, we are driven by a passion for code. Since our inception in 2000, we've dedicated ourselves to crafting the most powerful and efficient developer tools available. As AI-driven coding agents become integral to Kotlin development, we are committed to ensuring these tools excel in their purpose. The Kotlin AI Value Stream team plays a pivotal role in how AI agents comprehend, generate, and enhance Kotlin code across diverse platforms, including Android, Kotlin Multiplatform, server-side, web, and desktop applications. We develop evaluation infrastructures, error analysis tools, and post-training pipelines that assess and enhance agent performance on actual Kotlin developer tasks. In your role as a Research Engineer with our team, you will take charge of the complete feedback loop: Analyze failures in Kotlin code generated by agents, devise evaluations to identify those failures, research and implement strategies for improvement, and measure the outcomes. Your contributions will significantly influence how millions of developers interact with Kotlin through AI coding agents.

Are you a young academic talent in the STEM field ready to become one of the architects of the world’s most innovative simulation and training systems within military and civil aviation? Do you want to leverage your technical expertise to contribute to groundbreaking simulation technologies or master them? Join us in a collaborative environment with a multidisciplinary team of professionals in a cutting-edge high-tech setting. Here, you will not only have the opportunity for personal growth but also the resources to make a significant impact on our stakeholders! The success of aviation operations is no longer determined solely in the air but by the advanced simulations and training that precede them! – Achieve this with us.What Will You Do?As an R&D Engineer for Training Systems, you will focus on a broad development of knowledge regarding the latest simulation technologies, components, and architectures, and how to effectively and securely combine and integrate them into sustainable training system solutions for aviation. This role requires a solution-oriented and agile mindset to optimally align user requirements, desired and necessary functionality, and feasibility on technical, financial, and organizational levels. Collaborating with your colleagues, you will advocate for and connect the diverse interests of all involved stakeholders. Additionally, you will assist end-users in validating future and existing training systems, elevating these systems to a higher operational user level while ensuring compliance with aviation regulations. You will regularly collaborate with colleagues from other teams on various projects that deliver high-quality technological simulation and training solutions to end-users in aviation operations. Consider (inter)national networks with next-generation flight simulators for joint training of pilots and crew members in complex operational conditions, immersive XR environments for aircraft maintenance training, or AI-driven simulation systems supporting operational users of autonomous flying systems. Your role will also involve frequent contact and interactive working sessions with these users to develop groundbreaking comprehensive solutions. Your enthusiasm and willingness to enrich your understanding of the operational world of these users are essential. This will involve not only desk work but also on-site engagement with these operational users, along with regular collaboration with...

Join WPP Media as a Research Intern and immerse yourself in an innovative environment where creativity meets data-driven insights. As part of our dynamic team, you will assist in conducting comprehensive research that drives strategic decisions and enhances our client offerings. This is a unique opportunity for individuals eager to grow their skills in a fast-paced media landscape.

About LangChainAt LangChain, we are dedicated to making intelligent agents a cornerstone of modern technology. Our goal is to empower developers by providing the tools necessary to transition from initial prototypes to production-ready AI agents that teams can depend upon. Beginning as widely embraced open-source tools, we have expanded our offerings to include a robust platform for building, evaluating, deploying, and managing agents at scale.Our solutions, including LangChain, LangGraph, LangSmith, and Agent Builder, are trusted by teams developing real AI products across various sectors, from startups to Fortune 500 companies. Notable clients include Replit, Clay, Coinbase, Workday, Lyft, Cloudflare, Harvey, Rippling, and Vanta, representing 35% of the Fortune 500.With a successful Series B funding round raising $125M from esteemed investors such as IVP, Sequoia, Benchmark, CapitalG, and Sapphire Ventures, we are poised for significant growth. Every team member plays a critical role in shaping our products and company culture, making LangChain a dynamic environment for innovation and impact.About the RoleLocation: Amsterdam, NetherlandsCollaborate with pioneering companies to transform innovative ideas into production-ready applications in the realm of LLM.Engage in the development of a diverse range of LLM applications, including concierge search, code generation, and intelligent co-pilots.Deliver technical demonstrations showcasing the complete suite of LangChain's products.Facilitate training sessions and workshops focused on best practices for developer audiences.Work closely with the enterprise sales team to secure new deals.Collaborate with engineering teams to translate customer feedback into actionable product enhancements.Lead special projects that leverage our new products, both internally and externally.Success Factors in This RoleEngineers who are passionate about customer interactions and have aspirations of becoming future founders.Deployed engineers or solution architects with prior experience in developer-centric organizations.Candidates with an engineering background who thrive as trusted partners to clients.Individuals who are adept at finding innovative solutions and driving projects to success.

Why Join Nebius?Nebius is at the forefront of revolutionizing cloud computing to empower the global AI economy. We develop cutting-edge tools and resources that enable our clients to tackle real-world challenges and revolutionize industries, all while minimizing infrastructure costs and reducing the necessity for large in-house AI/ML teams. Our workforce operates at the forefront of AI cloud infrastructure, collaborating with some of the most experienced and innovative leaders and engineers in the industry.Our Work EnvironmentBased in Amsterdam and publicly listed on Nasdaq, Nebius boasts a global presence with R&D centers across Europe, North America, and Israel. Our diverse team of over 1400 professionals includes more than 400 highly skilled engineers excelling in both hardware and software development, complemented by an in-house AI R&D team.The RoleThis opportunity is part of Nebius AI R&D, a team dedicated to applied research in AI. Recent applied research published by our team includes:Applying reinforcement learning for agent training in long-context multi-turn scenariosDramatically scaling task data collection to enhance reinforcement learning for software engineering (SWE) agentsDeveloping a decontaminated evaluation system for SWE agents that is consistently updatedInvestigating test-time guided search methods to create more powerful agentsThe outcomes of our research frequently pave the way for collaboration with adjacent teams, allowing practical applications of our findings.We are currently seeking experienced ML engineers at the senior and staff levels to engage in research projects that include:Guided search and reinforcement learning for agentic systemsReinforcement learning applications for reasoning modelsWeb-scale data collection for agent trainingEfficient model distillation techniquesKey Responsibilities:Conducting experiments to identify effective methods for training large language models based on interaction traces with various environmentsExploring guided generation and search methodologies within trajectory spacesDevising innovative strategies for mining relevant data at web scale

Are you an ambitious young professional looking to apply your knowledge to make a significant impact on learning and performance in both military and civil aviation? We have the perfect challenge for you! Your RoleAs an R&D Engineer specializing in Training and Development, you will work within the training and simulation sector focused on (military) aviation. Your primary objective will be to investigate how to structure learning in the most effective and personalized manner, aiming to enhance performance in critical situations.This includes analyzing learning needs, designing training programs, developing innovative learning tools, expediting the readiness of military personnel, intelligently utilizing learning data, and integrating Artificial Intelligence into learning processes. Collaborating with a dynamic, multidisciplinary team, you will help shape the future of learning, with ample opportunity for your ideas, talents, and growth. Your Responsibilities Include:Analyzing learning and training needsDeveloping selection tools to support effective training intakeInvestigating the application and integration of innovative learning technologies while formulating functional requirements for (digital) training resourcesInterpreting learning data and contributing to the improvement of training designSetting up research, gathering and analyzing data, and translating results into actionable improvementsPresenting your findings at (international) meetings and contributing to knowledge sharing within and outside the organizationMaintaining client contact, identifying opportunities, and co-authoring proposalsThroughout all these tasks, you will work closely with colleagues and clients from practice. In summary, as an R&D engineer, you will hold a role with substantive depth and dynamism in a multidisciplinary environment!

Join the Loop TeamLoop Earplugs is transforming the way individuals interact with their environment, allowing them to control their auditory experience. In 2024, we celebrated significant milestones: surpassing 14 million earplugs sold, being recognized as 'The Best Earplugs for Concerts' by The New York Times, and expanding our offerings to provide comprehensive solutions for every situation. Additionally, we made history by being the first company to win Deloitte’s Fast 50 Belgium award twice.This is merely the beginning. As we innovate and create groundbreaking products, we seek visionary minds to join our team and help realize our ambitious goals.As a member of Loop, you will have the opportunity to make a substantial impact. No matter your role, this is your platform to bring your ideas to fruition while collaborating with a passionate global team of over 250 individuals who are grounded and enthusiastic about overcoming challenges together.Position: Director of Performance MarketingLocation: Antwerp or AmsterdamExperience: 10+ years in paid media, growth, and digital strategy Lead Performance Marketing and Propel Revenue GrowthThis is not just a lateral move; it's a leap into a performance-driven organization. You will command the entire acquisition engine—from paid social to influencer partnerships and affiliate marketing—transforming it into a global powerhouse. You will steer the strategy, oversee the team, conduct experiments, and manage expenditures. If you excel at metrics and are ready to challenge outdated methodologies, this is your opportunity to shine. No fluff, just impactful outcomes. The RoleYou will take ownership of the entire funnel, defining strategies for scaling our customer base during the next phase of global expansion. You will manage core acquisition channels efficiently while fostering innovation through structured experimentation. Your focus will be on achieving ambitious revenue targets across various channels.

Join Mollie as a Performance Marketer specializing in Affiliate Marketing. We are looking for a passionate and results-driven individual to enhance our affiliate program, optimize campaigns, and drive conversions. You will work closely with various partners to analyze performance metrics and implement strategies that boost our brand visibility and profitability.

Join Lenus Health as a Senior Performance Marketing Specialist in our vibrant Amsterdam office! Be a part of the health revolution! At Lenus, our mission is to create a healthier and happier world. If you envision yourself contributing to a meaningful purpose within a dynamic, global culture, you could be the perfect fit for our team. Who are we seeking? We are looking for a results-driven professional with expertise in paid social media campaigns. Are you passionate about empowering leading health and fitness coaches to grow their businesses? In this role, you will collaborate closely with some of Central Europe's foremost health and fitness coaches, providing them with innovative concepts and strategies while managing the creation, setup, monitoring, and optimization of their paid social advertisements. Your ability to craft compelling ad copy, analyze performance metrics, and effectively communicate insights and strategies will be essential. With our ongoing growth trajectory, the opportunity to make a significant impact at Lenus is boundless!

Join our dynamic team at Sia Partners as a Senior Consultant specializing in Financial Performance & Strategy. In this pivotal role, you will leverage your expertise to drive strategic financial initiatives for our clients, helping them achieve their goals and optimize their financial performance. Collaborate with cross-functional teams to provide actionable insights and recommendations that influence key business decisions. Your analytical skills and strategic mindset will be crucial in delivering high-quality consulting services.

Triangular Group seeks a Trainer for National Resilience Training to join the team in Amsterdam, Noord-Holland. The main focus of this position is to help strengthen resilience within both individuals and communities across the Netherlands. Key responsibilities Lead interactive sessions covering national resilience topics Develop and update educational materials that align with learning goals Collaborate with stakeholders to ensure training programs remain effective and up to date Location This role is based in Amsterdam, Noord-Holland, Nederland.

Join our innovative team at Pinely as a Quantitative Research Intern in Amsterdam! This internship provides a unique opportunity to delve into high-frequency trading (HFT) strategies, where you will collaborate with seasoned researchers and engineers. You will gain invaluable practical experience in applying advanced methodologies to real financial datasets. During this internship, you will engage in groundbreaking projects aimed at automating and enhancing trading strategies within a dynamic market environment. The duration of the internship ranges from 3 to 6 months, allowing for flexibility based on your availability. Successful candidates may receive a full-time job offer upon completion of the internship.Key ResponsibilitiesContribute to the research and development of innovative high-frequency trading strategies.Analyze existing HFT strategies and market microstructures to uncover new trading opportunities.Collaborate with developers and fellow researchers to implement and fine-tune trading strategies.Assist in refining current trading strategies and supporting quantitative strategy design efforts.QualificationsA strong passion for research and quantitative analysis.Solid understanding of probability theory and mathematical statistics.Proficient in Python and C++ programming languages.Familiarity with machine learning techniques is a plus.Exceptional performance in mathematical competitions or competitive programming contests.What We OfferWork alongside brilliant minds, including Kaggle Grandmasters and ACM ICPC World Finalists.Access to robust infrastructure for supporting your strategies and daily testing of ideas on a real-time production leaderboard.A modern, well-equipped workspace designed for productivity and comfort.A supportive work environment that prioritizes a healthy work-life balance.Participation in corporate and team events.

Join Adyen, a leading payment platform, as a Senior Manager in our Enterprise Offering team focused on Payment Performance. In this pivotal role, you will drive strategic initiatives to enhance payment solutions for our enterprise clients, ensuring they achieve optimal performance and efficiency. Collaborate with cross-functional teams to develop innovative offerings that meet the evolving needs of our diverse clientele.