Full-time · On-site (Paris Marseille Amsterdam) The sea is the physical layer of the economy—the conduit for our energy, communications, and trade. It is also Europe’s exposed flank. Pelagon is building the answer. Founded by Aymeric (serial deeptech entrepreneur; founded & exited Scortex, Leading AI solution for manufacturing quality) and Gauthier (Navy officer and McKinsey), Pelagon is building a foundational multimodal acoustic model for autonomous maritime protection (underwater and surface) in service of European sovereignty. It will be deployed on a distributed, autonomous network of vectors (UUVs, buoys, sailbuoys, seabed…) to provide real-time understanding of underwater threats. France and Europe have world-class acoustic engineers and a long history in underwater warfare. By bridging this expertise with modern physical-AI strategies (as seen in autonomous driving and robotics). Europe is still missing it’s naval NeoPrime, Pelagon aims to become to lead the way in autonomous marine protection—from detection to interception—partnering with leading navies, primes, and neo-primes, while also operating its own fleet as a service. Pelagon is backed by Hexa, the pioneer startup studio in Europe, which has launched 35+ companies, including unicorns like Front, Aircall, and Spendesk, combining €230m+ ARR and €750m raised.   Why this matters The sea is the physical layer of the economy — and Europe's most exposed flank. Everything that moves beneath the surface leaves an acoustic trace, but the ocean is a brutal channel: multipath, ambient noise, shifting propagation. Reading it is first and foremost a physics problem. France and Europe have a world-class heritage in underwater acoustics and sonar. Pelagon's bet is to bridge that science with modern physical-AI strategies and a distributed fleet of UUVs, buoys, sailbuoys and seabed sensors. As our Acoustic Researcher, you are the physics backbone of that system — the person who understands underwater sound deeply enough that our models can learn from it. You partner directly with our AI Engineers, who consume the features, representations and data you help define. What you'll do * Model underwater sound propagation across realistic ocean environments to enable our synthetic data generation pipeline. * Characterize and classify acoustic signatures of surface and underwater targets; build the ground-truth understanding our multimodal acoustic model is trained against. * Design and reason about sensor and array geometries: what to deploy, where, and how to extract maximum information from constrained & distributed vectors. * Work hand in hand with AI Engineers on physics-constrained learning strategies ans models. What we look for * Deep grounding in underwater acoustics, sonar, or a closely related field (ocean acoustics, radar/array processing, acoustic signal processing). PhD or equivalent research experience. * Strong command of statistical signal processing: detection & estimation theory, array processing, time-frequency analysis. * Fluent in Python (NumPy/SciPy) for modeling, simulation and analysis; comfortable working with large datasets. * A builder's instinct, you want your work deployed at sea, not left in a paper. Bias toward validating ideas against real data. * Bonus: prior experience using machine learning on acoustic signals, naval / defense domain experience.   Why join now * Founding ownership. You'll be one of the first engineers and will define the technical foundation of the company. Meaningful equity comes with that. * A mission with weight. This is hardware that protects critical infrastructure and Europe's maritime space. * Real things, in the real ocean, fast. You'll see your work in the water within weeks, not years. * AI-first, at the edge, in the real world. We train our own models and run them where it counts: in the water, on the device. You'll be solving the edge-ML and power problems most companies only talk about. * A sovereign, European deeptech at the inflection point of a market with strong NATO and EU policy momentum behind it.