LLM Engineer in London

At Ultralytics, we relentlessly drive innovation in AI, building the world's leading YOLO models. We're looking for passionate individuals obsessed with AI, eager to make a global impact, and ready to excel in a dynamic, high-energy environment. Join our team and help shape the future of Vision AI.

This full-time LLM Engineer position is based onsite in our brand-new Ultralytics office in London, UK. Applicants must have legal authorization to work in the UK, as Ultralytics does not provide visa sponsorship.

As an LLM Engineer at Ultralytics, you will spearhead the development and integration of advanced language model capabilities across our ecosystem. You will work on cutting-edge projects that merge the power of Large Language Models (LLMs) with our state-of-the-art computer vision technologies. Key responsibilities include:

• Developing and scaling robust LLM-powered applications using a variety of APIs, including OpenAI, Anthropic, and Gemini.
• Implementing and managing multi-API workflows using tools like LiteLLM to ensure flexibility and resilience.
• Building sophisticated Retrieval-Augmented Generation (RAG) systems, leveraging advanced techniques like embeddings with Voyage AI, rerankers, and query enrichment.
• Designing and maintaining efficient data pipelines and vector storage solutions using MongoDB Atlas Vector Search.
• Fine-tuning LLMs on custom datasets to enhance performance for specialized tasks related to our documentation and user support.
• Collaborating with our YOLO development team to explore and build innovative multi-modal solutions.
• Automating deployment and testing processes using CI/CD pipelines with GitHub Actions.

Your work will directly enhance the Ultralytics HUB platform and empower our global community of developers and researchers.

Skills and Experience:

• 5+ years of experience in software engineering, with a strong focus on AI and Machine Learning (ML).
• Expert-level proficiency in Python and deep learning frameworks, particularly PyTorch.
• Proven experience building and deploying applications with LLM APIs such as OpenAI, Anthropic, Gemini, and DeepSeek.
• Hands-on experience with the full RAG pipeline, including vector embeddings, rerankers, and data indexing in databases like MongoDB.
• Practical knowledge of LLM fine-tuning, prompt engineering, and performance optimization.
• Familiarity with MLOps principles and tools, including CI/CD with GitHub Actions.
• A strong interest in computer vision and an understanding of object detection models like Ultralytics YOLO11 is a significant plus.
• Excellent problem-solving skills and the ability to perform in a fast-paced, high-intensity environment.

Cultural Fit - Intensity Required:

Ultralytics is a high-performance environment for world-class talent obsessed with achieving extraordinary results. We operate at a relentless pace, demanding exceptional dedication and an unwavering commitment to excellence, guided by our mission, vision, and values. Our team thrives on audacious goals and absolute ownership. This is not a conventional workplace. If your priority is predictable comfort or a standard work-life balance over the relentless pursuit of progress, Ultralytics is not for you. We seek driven individuals prepared for the profound personal investment required to make a defining contribution to the future of AI.

Compensation and Benefits:

• Competitive Salary: Highly competitive based on experience.
• Startup Equity: Participate directly in our company's growth and success.
• Hybrid Flexibility: 3 days per week in our brand-new office - 2 days remote.
• Generous Time Off: 24 days vacation, your birthday off, plus local holidays.
• Flexible Hours: Tailor your working hours to suit your productivity.
• Tech: Engage with cutting-edge AI projects and contribute to leading open-source software.
• Gear: Brand-new Apple MacBook and Apple Display provided.
• Team: Become part of a supportive and passionate team environment.

If you are driven to redefine the capabilities of machine learning and eager to make a significant impact, Ultralytics offers an exceptional career opportunity.