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We are a team of passionate experts with a clear ambition: applying digital technology to advance what matters for our clients and society.

Together we create reliable and responsive digital foundations for the world’s businesses, institutions, and communities.

Learn more on Advancing what matters.

Atos is hiring a Lead AI Engineer to build and operate the model, infrastructure, and data layer of the Belgium AI delivery practice. The role trains and fine-tunes custom large and small language models for project use, builds and administers the AI infrastructure those models run on, and leads the data management, modelling, and integration work that every AI project depends on.

Key Responsibilities

• Build and train custom LLMs and SLMs. Fine-tune, align, and adapt models for project needs.
• Create and administer the AI infrastructure. Set up compute, serving, orchestration, autoscaling, and cost controls.
• Lead data management for AI projects. Build pipelines, vector stores, feature stores, and lineage tracking.
• Lead modelling decisions across the portfolio. Choose the right approach: foundation model, fine-tune, or custom SLM.
• Lead AI integration into project codebases. Connect models with project and client systems through APIs, retrieval layers, and agent frameworks.
• Run the evaluation harness for trained models. Define metrics, test sets, and CI-based quality gates.
• Partner with the AI Governance and Platform Lead on governance. Provide model cards, data lineage, evaluation results, and prompt documentation.
• Mentor delivery-team engineers. Support teams on model selection, fine-tuning, and data-quality practices.

Required Qualifications

• Bachelor’s or Master’s degree in Computer Science, Machine Learning, Engineering, or equivalent experience.
• 6+ years in ML engineering, deep learning, or AI platform engineering.
• 3+ years training, fine-tuning, or deploying LLMs in production.
• Experience with model tuning techniques such as LoRA, QLoRA, instruction tuning, RLHF, or DPO.
• and GPU infrastructure on a major cloud platform.