About Castelion

Castelion is bringing a new approach to defense development and production: one that focuses on short, iterative design cycles, rapid testing in development, and modern commercial manufacturing strategies for production at scale. We're designing, building, and testing next generation long range strike weapons systems to give America and its Allies a definitive edge and deter future conflicts.

FP&A Manager

We're seeking a highly analytical, execution-focused FP&A Manager to join our lean, high-impact team. In this role, you will own financial planning and visibility across a rapidly scaling defense hardware company. You'll lead budgeting, forecasting, and performance management processes that enable fast, confident decisions by our leadership and engineering teams.

This is not a sit-back-and-report role - you will build systems, models, and processes from the ground up. We're looking for someone who can dive deep, operate with incomplete information, and help shape the financial backbone of a company growing at extreme velocity.

Responsibilities

• Own the company-wide budgeting, forecasting, and long-range planning processes

• Build, refine, and maintain detailed financial models to inform strategic decision-making

• Manage monthly performance reviews, variance analysis, and reporting for leadership

• Partner directly with engineering, operations, supply chain, and program management to track spend vs plan, headcount forecasts, program budgets, and capital allocation

• Lead financial inputs for proposals, pricing models, and new customer opportunities

• Prepare materials for board meetings, investor updates, and internal operating reviews

• Design and implement scalable FP&A tools, dashboards, and processes as the company grows

• Mentor and guide junior team members and build the foundations of a future FP&A organization

Basic Requirements

• 4+ years of experience in FP&A, investment banking, management consulting, corporate finance, or similar roles
  (experience in aerospace/defense, manufacturing, or high-growth startups strongly preferred)

• Advanced financial modeling skills and strong command of Excel; experience with ERP/BI systems a plus

• Proven ability to work cross-functionally, gather inputs, pressure-test assumptions, and drive clarity

• High level of ownership, urgency, and comfort operating in a fast-changing environment

• Ability to distill complex technical and financial information into clear, actionable insights for leadership

Preferred Experience

• Direct experience with government proposals, DoD cost structures, or government contract pricing (e.g., FFP, T&M)

• Exposure to early-stage, vertically integrated manufacturing environments

• Interest in or passion for national security, aerospace, and building hardware that matters

All employees are granted long-term stock incentives as part of their employment at Castelion. All employees receive access to comprehensive medical, vision, and dental insurance, and the company offers four weeks of paid time off per year.

Leadership Qualities

Bias to Action and Creative Problem Solving. Desire and experience questioning assumptions in ways that lead to break through ideas that are ultimately implemented. Successfully bring in applicable processes/concepts/materials from other industries to achieve efficiency gains. Ability to personally resolve minor issues in development without requiring significant support.

High Commitment, High Initiative. A successful candidate will have a genuine passion for Castelion's mission and consistently look for ways to contribute to the company's technical goals and prevent hardware blockers. Ability to work in a fast paced, autonomously driven, and demanding atmosphere. Strong sense of accountability and integrity.

Clear Communicator. Proactively communicates blockers. Trusted in previous roles to be voice of company with regulators, suppliers, gate keepers and customers. Capable of tactfully managing relationships with stakeholders to achieve company-desired outcomes without compromising relationships. Emails, IMs and verbal interactions are logical, drive clarity, and detailed enough to eliminate ambiguity.

ITAR Requirements:

• To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.