Office Manager

Why Castelion, Why Now 

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.  

Office Manager

We are seeking a highly organized, proactive Office Manager to own the day-to-day operations of Castelion's Washington DC office, which serves as a key hub for customer engagement, executive meetings, and external events. This role is responsible for ensuring the office runs smoothly, professionally, and reliably.

This is not a traditional administrative office role this position is critical to shaping the first impression of Castelion for customers, partners, and stakeholders. You will manage operations, logistics, and experience within a high-visibility environment that frequently hosts important meetings, briefings, and events.

The ideal candidate is detail-oriented, operationally strong, and thrives in fast-paced environments where expectations for professionalism, responsiveness, and execution are high.

Responsibilities

• Own daily office operations, maintaining a clean, organized, and high-functioning environment
• Prepare and manage the office for customer visits, executive meetings, and hosted events, ensuring a seamless experience
• Coordinate meeting and event logistics end-to-end, including scheduling, setup, and execution
• Manage vendor relationships (janitorial, maintenance, catering, security), ensuring high-quality and timely service
• Oversee shipping and receiving, including handling, tracking, and distribution of mail, packages, and equipment
• Partner with EHS and security to uphold site protocols, visitor access procedures, and safe operations
• Maintain inventory of office supplies, equipment, and materials to ensure operational readiness
• Coordinate maintenance needs, addressing minor issues directly and escalating as appropriate
• Establish and uphold office procedures and SOPs to drive consistency and efficiency
• Ensure the office environment reflects a high standard of professionalism and aligns with Castelion's brand
• Track and manage office-related expenses and budgets
• Continuously identify and implement improvements to enhance office operations and overall workplace experience

Basic Qualifications

• 3+ years of experience in office management, operations coordination, facilities support, or related roles
• Strong organizational and multitasking skills with the ability to manage competing priorities
• Experience managing vendors, service providers, or operational workflows
• Familiarity with shipping/receiving processes and basic logistics coordination
• Strong communication and interpersonal skills, with experience supporting executives, customers, or external guests
• Proven ability to operate independently with high attention to detail and accountability
• Comfortable working in a fast-paced environment with frequent last-minute changes and high expectations
• Proficiency with standard office tools (Microsoft Office, Google Workspace, scheduling tools, etc.)

Preferred Skills and Experience

• Experience supporting executive offices, customer-facing environments, or high-visibility corporate spaces
• Background in facilities coordination, workplace operations, or logistics coordination
• Experience managing events, briefings, or customer visits in a professional setting
• Familiarity with EHS processes, security protocols, or controlled-access environments
• Experience working in aerospace, defense, industrial, or similarly regulated organizations
• Experience supporting small, high-performance teams in fast-growing companies
• Budget tracking or light financial administration experience
• Strong sense of ownership over physical space, logistics flow, and workplace experience

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 [email protected]. 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. 

EAR/ITAR Requirements 

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.