Group Cost Controller at Harmattan AI (Paris, France)Group Cost Controller

Harmattan AI is a next-generation defense prime building autonomous and scalable defense systems. Following the close of a $200M Series B, valuing the company at $1.4 billion, we are expanding our teams and capabilities to deliver mission-critical systems to allied forces. Our work is guided by clear values: building technologies with real-world impact, pursuing excellence in everything we do, setting ambitious goals, and taking on the hardest technical challenges. We operate in a demanding environment where rigor, ownership, and execution are expected.

As Group Cost Controller at Harmattan AI, you will take ownership of the Group’s Industrial, R&D & other operational costing, working closely with the FP&A Manager to structure, develop, and continuously improve Industrial P&L, Cost performance monitoring, and decision-support capabilities across multiple entities. The role combines hands-on analytical execution with higher-level structuring responsibilities, including Industrial P&L creation & development, Industrial & R&D cost planning, budgeting, forecasting, and KPI definition.

• Build the industrial P&L and the costing framework. Create the industrial P&L, define the standard cost calculation methodology, and set up the performance tracking processes that go with it.
• Monitor and challenge production and inventory performance. Track production costs, inventory levels and variances, identify deviations early, and work with operations to close them.
• Run the industrial management cycles. Initiate and own monthly closings, business reviews, forecasts and budgets for the industrial scope.
• Contribute to the Odoo implementation. Work with Production and Supply Chain to ensure inventory is tracked reliably in the system and that the outputs the business needs come out of it.
• Drive cost visibility and optimization beyond the plant. Follow R&D and project costs, and lead cost optimization initiatives across other operating costs.

Candidate Requirements

• Educational Background: Finance, Business Administration, Engineering, or a related field (Master’s preferred)
• Industrial Controlling Expertise: 5–8 years in cost or industrial controlling within a manufacturing environment or a complex production environment
• Modelling & Tools: Expert-level Excel and strong financial modelling skills, plus hands-on experience with an ERP . Comfortable with BOMs, standard costs and variance analysis.
• Builder's Mindset & Adaptability: Has built a controlling framework from a blank page rather than inherited one. Autonomous, structured, and at ease in a fast-moving environment where the answer does not exist yet.
• Business Partnering & Communication: A true business partner — curious about operations, comfortable on the shop floor, able to challenge production, engineering and procurement constructively. Fluent in French and English.

We look forward to hearing how you can help shape the future of autonomous defense systems at Harmattan AI.