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 and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

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

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.

Benefits And Perks

All full-time employees are granted meaningful long-term equity, sharing in the company's significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company-paid holidays, and comprehensive health benefits - including 100% employee-covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid parental leave to support growing families, a $100 monthly fitness stipend to promote health and performance, and onsite EV charging for convenience. In addition, employees enjoy perks like catered meals, company-covered food during high-demand periods, and a fully stocked kitchen to stay fueled throughout the day.

While this position does not currently require a U.S government-issued security clearance, it may in the near future. Therefore, the ability to obtain and maintain a U.S. government–issued security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance.

Affirmative Action/EEO Statement

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.