Senior Performance Testing Engineer

About OLIXAt OLIX, we are at the forefront of a technological revolution. With artificial intelligence evolving at an unprecedented pace, the demand for advanced infrastructure is soaring, creating a significant gap in the market. Current hardware approaches are outdated and unable to meet this demand. OLIX is pioneering a new paradigm with our Optical Tensor Processing Unit (OTPU), which promises unmatched performance and energy efficiency, setting the stage for the next great economic opportunity in the coming century.The RoleWe are looking for a passionate and skilled Staff Performance Modelling Engineer to take charge of creating and refining analytical and simulation models that will guide the evolution of our OTPU architecture and software. You will be responsible for developing functional simulators and high-fidelity, cycle-accurate models of our optical computing system. This pivotal role will allow you to explore diverse design possibilities and provide insights that shape our software and hardware roadmaps. If you thrive in a data-driven environment and enjoy rapid iteration, this position is designed for you.ResponsibilitiesOwnership: Define and execute the technical vision and roadmap for your team, aligning with OLIX's strategic technical and business objectives.Collaboration: Work closely with engineering teams to refine our system architecture and ensure that models are accurate and aligned with performance targets.Champion Modelling: Advocate for modelling methodologies and foster a culture of data-driven design across the organization.Functional Simulator: Design, build, and maintain a functional simulator for the OPTU subsystem and its full processing pipeline.Performance Simulator: Develop and maintain architectural and cycle-accurate models of the OPTU subsystems, identifying performance bottlenecks and proposing solutions.Workload Analysis & Bottleneck Hunting: Instrument various workloads to gather detailed performance traces for analysis.Design-Space Exploration: Conduct extensive parameter sweeps to evaluate trade-offs and inform decisions regarding software, hardware, and optical technologies.

About OLIXAt OLIX, we are at the forefront of an AI revolution, addressing the rapid growth and demand that has outpaced current infrastructure capabilities. The existing hardware frameworks are reaching their limits, and we are innovating a new paradigm to redefine efficiency and performance in computing. Our groundbreaking Optical Tensor Processing Unit (OTPU) sets a new standard for energy efficiency and performance, positioning OLIX to become a leader in the technology of the future.The Role:As the Engineering Manager for Performance Modelling, you will spearhead a dynamic team of six engineers focused on the architecture specifications of the OTPU. Your role involves validating these specifications through rigorous performance modelling techniques including roofline, functional, cycle-accurate, and power modelling. Collaborating closely with compiler, ASIC, product, and business development teams, you will ensure that architectural decisions align with customer needs and business objectives.We seek a seasoned engineering manager who can inspire a talented team to achieve impactful results for our clients and the business. Your deep technical expertise and proven ability to foster a collaborative and high-performing team culture will be crucial to navigating the complexities of hardware/software co-design.

Who are we?At Cohere, our mission is to harness and scale intelligence for the betterment of humanity. We are dedicated to training and deploying cutting-edge models that empower developers and enterprises to create astonishing AI-driven experiences such as content generation, semantic search, retrieval-augmented generation (RAG), and intelligent agents. We believe that our innovations play a crucial role in the mainstream adoption of AI technologies.We take great pride in the products we develop. Every team member contributes to enhancing our models' capabilities and the value they deliver to our customers. Our culture is driven by hard work and a commitment to swift execution that prioritizes our clients' needs.Cohere is composed of a diverse team of researchers, engineers, designers, and more, all of whom are passionate about their respective fields. Each individual is among the best globally in their area of expertise. We firmly believe that a wide array of perspectives is essential for creating outstanding products.Join us in our quest to shape the future of AI!Why this role?As a Performance Engineer within our Pre-Training team, you will play a pivotal role in optimizing the efficiency and performance of our advanced language models and systems. Your primary focus will be on enhancing critical model training metrics, including training throughput and maximizing accelerator utilization.This team merges software engineering, machine learning, and low-level kernel design expertise to develop robust systems that elevate model performance. You will actively identify and eliminate performance bottlenecks, while also creating innovative training and profiling tools that support Cohere's mission of delivering efficient and reliable language understanding and generation capabilities, thereby driving advancements in natural language processing.Note: While we have offices in London, Toronto, New York, and San Francisco, we are also remote-friendly! This team primarily operates between Eastern Time (ET) and Central European Time (CET), so we are looking for candidates in locations aligned with these time zones for effective collaboration.As a Technical Staff Member, your responsibilities will include:Crafting and developing high-performance, scalable software solutions for model training.Comprehending architectural modifications and design choices and their impacts on training throughput and quality.Writing low-level CUDA and Triton kernels to maximize performance from our accelerators.Conducting research, implementation, and experimentation on our supercomputing and data infrastructure.Collaborating with and learning from top researchers in the field.

Join xai as a Technical Staff Member focusing on Model Training. In this role, you will collaborate with a talented team to develop and optimize machine learning models that drive innovative solutions. Your expertise will contribute to enhancing the performance of our systems and delivering impactful results.

Location: LondonCompany: H About H H is focused on building agentic AI that automates complex, multi-step tasks typically handled by people. The company’s goal is to help individuals achieve more by creating superintelligent systems that work safely and responsibly. H values openness, continuous learning, and collaboration. Every team member’s input matters here. About the Models Team The Models team develops the core models that power H’s agentic AI technology. This group works on training methods to boost model performance and efficiency, especially for agent-driven applications where inference costs matter. Projects span Large Language Models (LLMs) and Vision-Language Models (VLMs), enabling agents to interpret and interact with complex environments. Team members refine these models using advanced training approaches, including reinforcement learning and reward modeling. The focus is on better instruction following, tool use, and dynamic interaction. The team’s work bridges research and product, turning new research into practical solutions that move AI forward. Who Hires Here H seeks exceptional AI researchers and engineers from around the world who care about advancing technology safely and responsibly. The company welcomes those eager to shape the future of superintelligent AI alongside a collaborative and driven team.

Join Our TeamLatent Labs is on the lookout for a talented Machine Learning Research Engineer with extensive expertise in training and deploying large-scale generative models. In this pivotal role, you will oversee our high-performance computing infrastructure and drive our model serving initiatives. You will collaborate with a diverse team of machine learning experts, protein engineers, and biologists, all dedicated to transforming how we manipulate biological systems and develop innovative treatments for diseases.About Latent LabsAt Latent Labs, we are pioneers in creating advanced models that grasp the core principles of biology. Our team, which once co-developed DeepMind's groundbreaking AlphaFold and invented latent diffusion, is committed to scientific rigor and ambitious exploration. By joining us, you will work alongside some of the most brilliant minds in the fields of generative AI and biology, fostering a culture of collaboration and continuous learning between our London and San Francisco offices.We seek innovators who are passionate about solving complex problems and making a positive impact on the world. Be a part of our ambitious mission!

About Gridcog Gridcog is a SaaS start-up focused on advancing the clean energy transition. The team brings together energy professionals building project modeling software that helps users make informed, strategic decisions about energy projects. Role Overview This Senior Simulation Engineer (Modeling) position centers on improving and expanding the simulation and optimization capabilities within Gridcog’s Python codebase. The work blends mathematical modeling, numerical methods, and production-level software engineering to deliver accurate, efficient, and reliable simulations at scale. What You Will Do Enhance and extend simulation and optimization features in the core Python platform Work with mathematical models and numerical methods to support complex energy project scenarios Ensure modeling outputs remain accurate and efficient as the platform grows About the Platform The Gridcog platform models the physical and commercial aspects of energy projects. It integrates technologies such as solar, wind, batteries, flexible loads, gensets, and EV fleets, capturing their interactions within electricity markets and tariff structures worldwide. Who Should Apply Simulation engineers with experience in modeling uncertainty and solving complex business problems Candidates with backgrounds in energy systems modeling are encouraged, but those with transferable skills from other modeling or data science domains will also be considered Location This position is based in London, England, United Kingdom.

Intercom builds tools that help businesses deliver better customer service, powered by artificial intelligence. Nearly 30,000 companies worldwide use Intercom’s products, including Fin, an AI customer service agent that works seamlessly with the Intercom Helpdesk as part of the Customer Service Suite. Since 2011, Intercom has focused on innovation and delivering value for clients. Role overview The AI Models Infrastructure Team within Intercom’s AI Group develops and maintains the core infrastructure that supports the company’s proprietary AI models. Intercom is hiring an Engineering Manager to lead this team. This is a technical leadership position working at the intersection of infrastructure and artificial intelligence. What you will do Guide a team of engineers building and operating the infrastructure for Intercom’s AI models Work closely with other teams to ensure the reliability and scalability of AI systems Support ongoing technical growth within the team and stay current with advances in AI Who we’re looking for Experience managing technical teams, ideally in AI or related fields Strong background in infrastructure or platform engineering Commitment to continuous technical development Locations Berlin, Germany Dublin, Ireland London, England Learn more About engineering at Intercom: https://intercom.engineering About Fin: http://fin.ai

Join Our Team as a Senior Modelling Engineer II!At Runna, we are assembling a dynamic team dedicated to creating the leading training platform for runners worldwide. Our mission is to empower everyday runners to excel by providing an exceptional app that offers top-tier training, coaching, and a supportive community, whether you're aiming to improve your 5k performance or preparing for your first marathon.Our growth has been remarkable! In November 2023, we successfully closed a $6.5 million funding round led by JamJar, with contributions from Eka Ventures, Venrex, and Creator Ventures. In 2024, we were honored to be recognized by Apple as one of the three global finalists for the iPhone App of the Year, showcasing the innovation and impact of our platform. Furthermore, in 2025, we became part of the Strava family!Our ambition is bold: to be the premier global training platform for millions of runners around the globe. As we accelerate our journey with the recent acquisition by Strava, now is an exciting time to become a part of something significant. The Train Team, a cross-functional group of over 35 professionals, is at the core of Runna’s mission: delivering outstanding training experiences to hundreds of thousands of runners globally. We focus on creating and dynamically adjusting optimal, personalized training plans at scale, analyzing performance data for training adjustments, and providing users with valuable insights based on their training and environment.We embrace a flexible hybrid working model, requiring you to be on-site three days a week at our London office.

Join Our Visionary Team at Runna!At Runna, we are on a mission to create the premier training platform for runners. Our innovative app empowers everyday athletes to excel, providing access to top-notch training, expert coaching, and a supportive community whether you're aiming to improve your 5k or preparing for your first marathon.Our rapid growth is fueled by a strong vision, backed by a recent $6.5M funding round led by JamJar and supported by Eka Ventures, Venrex, and Creator Ventures. In 2024, we had the honor of being named one of Apple’s three global finalists for the iPhone app of the year, and in 2025, we proudly became a part of Strava!We aspire to be the leading global training platform for millions of runners. With our recent acquisition by Strava accelerating our growth, this is an exciting time to join us. As part of our dynamic Train Team, which includes over 35 professionals from engineering, product, design, and coaching, you will play a crucial role in delivering exceptional training experiences to hundreds of thousands of runners worldwide. You will engage in developing personalized training plans at scale, analyzing performance data, and providing insights to our users based on their training and environmental conditions.We embrace a flexible hybrid working model, requiring you to be on-site three days a week at our London office.

Begin your journey with us and thrive in your career.Are you eager to collaborate with a team of skilled modellers dedicated to revolutionizing the water sector?Join our innovative and diverse Water Team as a Senior Wastewater Hydraulic Modeller. You will have the flexibility to work from one of our offices in the UK or Ireland while benefiting from our adaptable hybrid working arrangement.As a vital contributor, you will play an essential role in executing transformative water projects both within the UK and internationally. We are committed to developing significant flood mitigation strategies, enhancing pollution control measures, and advancing infrastructure initiatives. This diversity of projects will be pivotal for your ongoing professional growth. Our unique methodology integrates our modelling team with broader project teams, allowing for close collaboration with experts across various disciplines to devise comprehensive solutions.As a leading authority in Blue-Green infrastructure and nature-based solutions, we partner with both public and private sector clients such as Severn Trent, Anglian Water, Northern Ireland Water, the Environment Agency, LLFAs, and several other infrastructure providers. Our offerings include Flood Risk Assessments, Drainage Strategies, Outline Business Cases, hydraulic models, and detailed designs. We establish industry benchmarks by providing guidance that defines best practices, positioning AECOM at the forefront of the water industry. This role presents a remarkable opportunity to contribute to a talented and diverse team devoted to innovation, teamwork, and efficiency.Your responsibilities will include:Model Development: Construct hydraulic models and validate sewer networks; oversee integrated model development, assist in project scoping and planning, including flow survey validation, and devise catchment-wide strategic solutions addressing flooding and pollution challenges.Technical Expertise: Drive technical innovation through the application of cutting-edge technologies; develop solutions for our clients and create project scopes and tender responses.Reporting: Prepare and present technical reports, presentations, and documentation to effectively communicate modelling outcomes utilizing strong communication skills.Leadership: Mentor and guide team members in their professional development and cultivate positive relationships with clients.Quality Assurance: Review hydraulic models, calculations, and technical reports to ensure adherence to quality standards and compliance with modelling specifications.If you are passionate about innovation and transforming ambitious ideas into reality, AECOM invites you to join us. Be part of a team that not only builds infrastructure but also uplifts communities and enhances lives. Follow our AECOM Water page on LinkedIn for updates on our projects and initiatives.

AECOM is seeking a Senior or Principal Civil 3D Modeller to support infrastructure projects in London. This role centers on applying advanced Civil 3D skills to produce accurate models for a range of engineering and construction initiatives. Role overview Work closely with multidisciplinary teams to develop and refine design solutions. The position involves creating detailed models that support project delivery and contribute to effective collaboration across engineering disciplines. What you will do Use Civil 3D to generate and manage models for infrastructure projects Coordinate with colleagues from various specialties to ensure integrated project outcomes Support design innovation and maintain high standards of quality in modelling work Requirements Extensive experience with Civil 3D software Background in infrastructure or related engineering projects Strong collaboration and communication skills

At Hudl, we pride ourselves on cultivating exceptional teams. We recruit top-tier talent to ensure you work alongside individuals who inspire continuous learning. You will be empowered to accomplish your tasks in your own unique style while pushing the boundaries of innovation and creativity. Our supportive culture is reflected in the recognition we've received, including being named one of Newsweek's Top 100 Global Most Loved Workplaces. As the backbone of the sports world, we understand the lasting impact that sports can have, from teaching teamwork and commitment to inspiring coaches and unlocking potential. Our solutions are designed to help athletes and teams worldwide enhance their performance by simplifying video capture, data analysis, and highlight sharing.Are you ready to be part of our mission?Your RoleWe are looking for Senior Engineers to join our dynamic Human Performance team, dedicated to developing innovative solutions for athletes and sports teams that transform training, competition, and peak performance.Your responsibilities will include:Cross-Functional Collaboration: Partner with Engineering, Quality Assurance, Product, Design, and Scrum teams to create comprehensive full-stack web features.Development and Delivery: Enjoy the autonomy to make significant contributions to the product area, responding to customer needs and delivering breakthrough features that empower our coaches and athletes.Idea Testing: Participate in rapid iterations, deploying updates to the product hundreds of times daily. You'll also have the chance to address complex technical challenges and mentor junior engineers.Mentorship: Share your knowledge and guide others on development best practices, exemplifying excellence in planning, design, and execution of intricate projects.

Intercom builds AI-powered customer service products for businesses worldwide. Nearly 30,000 companies use Intercom’s solutions to deliver support and improve customer engagement. The company’s AI agent, Fin, provides around-the-clock customer service and integrates with Intercom’s Helpdesk as part of the broader Customer Service Suite. For complex or sensitive queries, the suite enables seamless handoff to human agents. Role overview The AI Models Infrastructure Team sits within Intercom’s AI Group and develops the core systems for training and deploying proprietary AI models. As Engineering Manager for this team, lead a group of engineers focused on building and maintaining the technical foundation that powers Intercom’s AI capabilities. What you will do Guide and support a team of engineers working on AI infrastructure projects Oversee the design, development, and operation of systems for training and deploying AI models Stay current with advances in AI and infrastructure, applying new knowledge to team projects Foster technical growth and collaboration in a fast-evolving field What you bring Previous experience in AI or machine learning engineering Background in building and operating technical infrastructure Strong interest in deepening technical expertise Experience leading or mentoring engineers Location This position is based in London, England. Learn more About Intercom’s engineering culture: intercom.engineering About Fin: fin.ai

Join Anthropic as a Staff Software Engineer on our Inference team, where you will play a pivotal role in building and maintaining the essential systems that power Claude for millions of users globally. This position involves overseeing the complete stack—from intelligent request routing to fleet-wide orchestration across various AI accelerators. You will focus on enhancing compute efficiency to support our rapid user growth while enabling groundbreaking research through high-performance inference infrastructure. As a key player in tackling complex distributed systems challenges, you will help shape the future of AI technology.

aisi seeks a Research Engineer or Research Scientist to focus on Model Transparency in London, UK. The position involves research aimed at making AI models more understandable and accountable. The goal is to clarify complex behaviors within these systems and help build trust in their outcomes. Key responsibilities Research new ways to improve the interpretability of AI models Create methods and tools that help explain how models make decisions Tackle challenges in understanding and communicating model behavior Contribute to initiatives that support greater accountability in AI Location This role is based in London, UK.

Join Monzo as a Senior Forecasting Modeller, where you will leverage advanced analytics to shape our financial forecasts. Your expertise will guide decision-making processes and enable us to enhance our strategic planning. You will collaborate closely with cross-functional teams to develop robust predictive models that drive business growth and improve operational efficiency.

Join our innovative team at Egis Group as a Senior Wastewater Modeller, where you will play a pivotal role in the design and analysis of wastewater systems. You will leverage advanced modelling techniques to enhance the efficiency and sustainability of our projects. This is an exciting opportunity to work on impactful projects that contribute to environmental sustainability.

Join our dynamic Machine Learning team at Jane Street as a Machine Learning Performance Engineer. We are seeking an innovative engineer with a strong background in low-level systems programming and performance optimization. Machine learning is fundamental to Jane Street's operations, providing a unique rapid-feedback environment for experimentation and real-time application in our trading strategies. Your role will focus on optimizing the performance of our machine learning models, enhancing both training efficiency and inference speed. We prioritize efficient large-scale training, low-latency inference for real-time systems, and high-throughput inference for research purposes. Your contributions will involve not just improving CUDA performance but also adopting a holistic systems approach that encompasses storage systems, networking, and GPU-level considerations. We aim to ensure that our infrastructure is optimized at every level, from memory access to overall throughput. If you have a curious mind and a passion for tackling complex problems, regardless of your background in finance, you will find a welcoming environment here at Jane Street.