Senior Software Engineer

The role This role is for Nebius AI R&D, a team focused on applied research and the development of AI-heavy products. Examples of applied research that we have recently published include: investigating how test-time guided search can be used to build more powerful agents; dramatically scaling task data collection to power reinforcement learning for SWE agents; maximizing efficiency of LLM training on agentic trajectories. One example of an AI product that we are deeply involved in is Nebius Token Factory — an inference and fine-tuning platform for AI models. This role will require expertise in distributed systems to build large-scale LLM training platform. Your responsibilities will include: Designing and developing LLM training platform. Maintaining our ML infrastructure, ensuring optimal performance, scalability and reliability. Improving job scheduling strategies to minimize resource fragmentation. We expect you to have: 5+ years of professional software development experience. Strong software engineering skills (we mostly use Python and Go). Proficiency in contemporary software engineering approaches, including CI/CD, version control and unit testing. Experience with developing web services. A commitment to maintaining extreme rigor in all job-related activities. Nice to have: Previous experience working with language models or other similar NLP technologies. A track record of building and delivering products (not necessarily ML-related) in a dynamic startup-like environment. Strong engineering skills, including experience in developing large distributed systems or high-load web services. Open-source projects that showcase your engineering prowess. Benefits & Perks: Competitive compensation Career growth and learning opportunities Flexibility and ownership Collaborative and innovative culture Opportunity to work on impactful AI projects International environment and talented teams What's it like to work at Nebius: Fast moving - Bold thinking - Constant growth - Meaningful impact - Trust and real ownership - Opportunity to shape the future of AI Equal Opportunity Statement: Nebius is an equal opportunity employer. We are committed to fostering an inclusive and diverse workplace and to providing equal employment opportunities in all aspects of employment. We do not discriminate on the basis of race, color, religion, sex (including pregnancy), national origin, ancestry, age, disability, genetic information, marital status, veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by applicable law. Applicants must be authorized to work in the country in which they apply and will be required to provide proof of employment eligibility as a condition of hire. If you need accommodations during the application process, please let us know.