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…