Financial Controller - #54882

Job Description

Who we are :

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.

Following our Series A, we're delivering FLOW: the most ambitious Natural Hydrogen drilling campaign to date, across multiple geographies with leading industrial partners. Goal: select 2-3 top locations globally (Europe, Middle East, Africa, North America) and prove a commercially exploitable reservoir combining high pressure, high purity, and multi-megaton scale, unlocking sub-€1/kg hydrogen, a new sovereign energy source.

What The Role Is About

As Financial Controller, you'll join Mantle8's finance team and drive financial planning and management control (FP&A / contrôle de gestion) — supporting our growth and industrial/exploration projects. You'll own budget construction and reforecasts, FP&A and variance analysis, treasury and monthly close, project-level controlling, and the financial infrastructure (tools, workflows, external accountant interface) supporting decisions across the TopCo and the SPVs.

The role requires the analytical rigour of a controller, the operational discipline to close the books on time every month, and an entrepreneurial mindset — comfortable rolling up your sleeves in a lean team.

What You'll Be Doing

• Build the annual budget and recurring reforecasts for the TopCo and SPVs; produce budget vs actuals analyses.
• Develop cash-flow forecasts and runway projections; communicate cash/runway views to the executive team.
• Manage bank accounts, execute payments, run reconciliations, and drive the monthly close.
• Track analytical accounting by project, department, and technology.
• Prepare financial data and documentation for CIR (Crédit Impôt Recherche) and grant/subsidy applications.
• Deploy and improve financial tools, structure expense-commitment workflows, and act as the interface with the external accountant and operational teams.
  
  

What We Offer

• Corporate welfare plan & supplementary health insurance
• Indefinite contract (CDI) with full French employment protections
• A meaningful role building a new clean, affordable, sovereign energy source
• High-exposure role at the financial core of a fast-growing clean-tech start-up, direct interface with the CFO, COO, and all functions
• Collaborative, dynamic, diverse work environment in the stunning French Alps
  
  

Mantle8 is an equal opportunity employer committed to diversity and inclusion.

Requirements

What we're looking for :

Essential

• Solid experience (+5years) in FP&A and management control (contrôle de gestion)
• Experience building annual budgets and reforecasts in a multi-entity context (TopCo + SPVs)
• Experience producing budget vs actuals analyses
• Experience with cash-flow forecasting and runway projection
• Experience with bank operations, payment execution, and bank reconciliations
• Experience driving monthly close
• Fluent in French and English, both oral and written
  
  

Highly Valued

• Experience preparing financial data for CIR and grant/subsidy applications
• Experience with analytical accounting across multiple axes (project/department/technology)
• Experience deploying or improving financial tools in a startup or scale-up environment
• Experience structuring expense-commitment workflows
• Experience interfacing with external accountants and operational teams
• Prior experience in a high-growth startup or scale-up environment
• Strong alignment with Mantle8's mission to unlock a new, sovereign, low-carbon energy source