Proposal Manager Torrance, CA Program Management

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we're building a world-class team to turn bold ideas into real capability.

This is a rare opportunity to join at an early stage, where you'll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function.

Proposal Manager

As the Proposal Manager at Castelion, you will own the development and submission of high-quality proposals to Department of War customers. This role is responsible for the proposal process end to end: understanding the customer and opportunity, shaping the response strategy, structuring the proposal, building the compliance framework and schedule, coordinating inputs across the company, writing and editing technical and programmatic content, and ensuring the final submission is complete, compliant, compelling, and on time.

This is a hands‑on writing and leadership role. You must be able to understand Castelion's technology and programs deeply enough to translate complex engineering concepts into clear, credible proposal language, while tuning the message to the customer's mission, acquisition context, evaluation criteria, and underlying needs. You will report directly to the Head of Programs and work closely with engineering, program management, business development, contracts, finance, manufacturing, test, and executive leadership.

Responsibilities

• Own proposals from kickoff through submission: Lead the full proposal lifecycle for competitive solicitations, white papers, RFIs, RFPs, OTAs, BAAs, and other DoW opportunities. Establish the proposal plan, schedule, roles, review cadence, and submission strategy, and drive the team to each deadline.
• Develop proposal strategy and structure: Translate solicitation requirements, customer context, evaluation criteria, and capture strategy into a clear response architecture. Build outlines, technical content, compliance matrices, page budgets, and win themes that create a coherent and persuasive narrative.
• Write and shape the message: Draft, rewrite, and edit technical, programmatic, management, schedule, manufacturing, test, and execution content. Tailor messaging to the specific customer and acquisition environment so that the proposal directly addresses what the customer needs, why Castelion is differentiated, and how we will execute.
• Understand and communicate Castelion technology: Develop sufficient technical fluency in Castelion products, architectures, manufacturing approaches, test programs, and operational concepts to independently produce accurate technical writing and identify where additional engineering input is required.
• Gather and integrate cross-functional inputs: Work across engineering, programs, manufacturing, supply chain, test, finance, contracts, security, and business development to collect inputs, resolve gaps and inconsistencies, and turn fragmented source material into a single integrated response.
• Drive compliance and proposal quality: Own the compliance matrix and ensure every solicitation instruction, requirement, evaluation factor, attachment, representation, and submission condition is addressed. Conduct detailed reviews for accuracy, consistency, responsiveness, clarity, and completeness.
• Manage proposal reviews and iteration: Plan and facilitate structured proposal reviews, capture decisions and actions, adjudicate comments, and rapidly iterate the proposal toward a final product. Maintain control of the master document and ensure changes are integrated cleanly.
• Own formatting and final production: Take responsibility for document formatting, graphics integration, tables, cross-references, page limits, file structure, naming conventions, and final production. Ensure the submission is polished, easy to evaluate, and fully compliant with customer instructions.
• Submit proposals on time: Own final packaging and submission through the required customer portal, email, consortium system, or other delivery mechanism. Verify all volumes, attachments, signatures, certifications, and files are complete and successfully delivered before the deadline.
• Improve Castelion's proposal capability: Build and continuously improve proposal templates, reusable content, workflows, review standards, content libraries, and lessons learned so the company can respond faster and with higher quality as the opportunity pipeline grows.

Basic Qualifications

• 5+ years of experience developing and writing proposals for Department of Defense and/or Intelligence Community customers.
• Demonstrated experience writing/leading proposals from solicitation release through final submission, including planning, compliance, writing, reviews, production, and delivery.
• Excellent technical writing skills, with the ability to turn complex or incomplete source material into clear, concise, customer-focused content.
• Strong understanding of DoD/IC solicitations, proposal instructions, evaluation criteria, and government acquisition environments.
• Ability to quickly learn complex technical systems and work directly with engineers and technical leaders to produce accurate technical content.
• Exceptional attention to detail and the ability to manage multiple contributors, deadlines, volumes, and requirements without losing ownership of the final product.
• Strong judgment and communication skills, including the ability to challenge weak inputs, identify gaps, and drive decisions across senior and cross-functional stakeholders.

Castelion offers a generous benefits package. Please refer to the bottom of our Careers page for more details.

Other Duties

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice.

Additional Eligibility Requirements

This position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply.

Affirmative Action/EEO Statement

Castelion is an Equal Opportunity Employer. We are committed to providing equal employment opportunities to all applicants and employees without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, genetic information, protected veteran status, or any other characteristic protected by applicable federal, state, or local law.

Castelion is committed to providing reasonable accommodations to qualified individuals with disabilities throughout the application and hiring process. If you require a reasonable accommodation to complete an application, participate in the interview process, or otherwise participate in the hiring process, please contact View email address on click.appcast.io. Requests for accommodation will be considered on an individual basis and handled in accordance with applicable law.

Castelion is committed to fostering a workplace where employment decisions are based on qualifications, business needs, and the ability to perform the essential functions of the role, with or without reasonable accommodation.

This position requires access to export‑controlled information, and as such, employment (or hiring of a contractor) is contingent upon the candidate’s ability to access all applicable export‑controlled information without additional export licensing being required by the Bureau of Industry and Security and/or the Directorate of Defense Trade Controls.