AI / Machine Learning Engineer

As AI / Machine Learning Engineer, you'll join Mantle8's Data Team, reporting to the Data Lead, applying AI/ML to accelerate workflows company-wide - from technical R&D to portfolio decisions. You'll work closely with geoscience, exploration, and technology teams to improve Simul8 (our hydrogen digital twin), HOREX (our 4D subsurface imaging tech), portfolio decisions, and our data infrastructure. The role requires deep AI/ML fluency, curiosity to spot high-leverage use cases in subsurface/clean-tech, and an entrepreneurial mindset - comfortable owning models end-to-end in a lean team.

What you'll be doing :

• Improve Simul8 and HOREX with AI surrogates, neural-network architectures, and production-grade pipelines.
• Bring AI into portfolio management: play assessment, prospect ranking, Go/No-Go decisions, decision-grade insights for leadership.
• Build AI agents that autonomously explore Mantle8's datasets/dashboards.
• Design, train, and industrialise neural-network models across modalities (geophysical signals, geological models, tabular data, text), with rigorous evaluation on subsurface/physics-constrained problems.
• Prototype new AI use cases across teams; upskill the team on AI tools and data workflows.

What we offer :

• Corporate welfare plan & supplementary health insurance
• Indefinite contract with full French employment protections
• A meaningful role building a new clean, affordable, sovereign energy source
• Significant impact in a fast-growing clean-tech start-up, in the French Alps

• Minimum 5 years of professional experience applying AI/ML workflows
• Hands-on fluency with the modern ML stack (pipelines, training infrastructure, model evaluation, MLOps)
• Experience with AWS (S3, EC2, RDS) and production databases, ideally PostgreSQL
• Proven ability to work with unstructured/non-tabular data (text, PDFs, images, geospatial data)
• Fluent English (spoken and written), the team operates in English daily
• Master's in AI, Machine Learning, Data Science, or related field
• Strong grasp of neural networks and modern frameworks (PyTorch, TensorFlow, Scikit-learn, JAX, Spark, Ray)
• Demonstrated portfolio of AI/ML use cases (open-source, internships, theses, or production deployments)
• Strong analytical mindset, comfortable turning ambiguous problems into clean solutions
• Comfortable in a fast-paced, lean team, owning models end-to-end

Highly valued:

• Interest in the energy transition and clean-tech
• Physics-informed neural networks or simulation surrogates
• RAG (retrieval augmented generation) experience in production
• Exposure to subsurface, geoscience, or geophysics use cases
• Experience building agentic AI systems (LLM agents, tool use)
• Experience with Databricks in production
• Willingness to relocate to the Grenoble area, French Alps
• Startup/scale-up experience; familiarity with French HPC ecosystems

Mantle8 is a clean-tech start-up revolutionizing natural hydrogen exploration, backed by investors including Breakthrough Energy Ventures and Kiko Ventures. We combine geoscience, 4D seismic imaging, big data, and AI to identify prospective natural hydrogen areas worldwide., Mantle8 is a deep-tech exploration company dedicated to unlocking the potential of natural hydrogen as a new clean energy resource. By combining advanced geoscience, subsurface modeling and cutting-edge simulation technologies, Mantle8 develops innovative exploration methods to identify and evaluate natural hydrogen systems deep within the Earth. Our multidisciplinary team brings together geoscientists, engineers, data scientists and explorers who share a common ambition: advancing scientific understanding while building the foundations of a new energy frontier. From regional exploration concepts to prospect generation and technological development, Mantle8 works at the intersection of research, innovation and industrial application to accelerate the emergence of natural hydrogen as part of the global energy transition. At Mantle8, exploration is not only about discovering new resources - it is about expanding knowledge, challenging assumptions and building solutions for the future of energy. Why is everything in English if Mantle8 is based in the heart of the French Alps? Because Mantle8 is an international adventure. As of March 2026, our team includes 21 people representing 9 different nationalities. This diversity is one of our greatest strengths, and English is the language that allows everyone to collaborate, debate ideas and build things together. We love our home in the French Alps, but inside Mantle8 our common ground is English - from meetings and technical discussions to emails and, yes, even our jokes. So if you're thinking about joining us, English is not just helpful - it's essential to be part of the conversation.