Office ManagerWashington D.C., District of Columbia, United StatesAbout the JobCastelion 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.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.ResponsibilitiesOwn daily office operations, maintaining a clean, organized, and high-functioning environmentPrepare and manage the office for customer visits, executive meetings, and hosted events, ensuring a seamless experienceCoordinate meeting and event logistics end-to-end, including scheduling, setup, and executionManage vendor relationships (janitorial, maintenance, catering, security), ensuring high-quality and timely serviceOversee shipping and receiving, including handling, tracking, and distribution of mail, packages, and equipmentPartner with EHS and security to uphold site protocols, visitor access procedures, and safe operationsMaintain inventory of office supplies, equipment, and materials to ensure operational readinessCoordinate maintenance needs, addressing minor issues directly and escalating as appropriateEstablish and uphold office procedures and SOPs to drive consistency and efficiencyEnsure the office environment reflects a high standard of professionalism and aligns with Castelion's brandTrack and manage office-related expenses and budgetsContinuously identify and implement improvements to enhance office operations and overall workplace experienceBasic Qualifications3+ years of experience in office management, operations coordination, facilities support, or related rolesStrong organizational and multitasking skills with the ability to manage competing prioritiesExperience managing vendors, service providers, or operational workflowsFamiliarity with shipping/receiving processes and basic logistics coordinationStrong communication and interpersonal skills, with experience supporting executives, customers, or external guestsProven ability to operate independently with high attention to detail and accountabilityComfortable working in a fast-paced environment with frequent last-minute changes and high expectationsProficiency with standard office tools (Microsoft Office, Google Workspace, scheduling tools, etc.)Preferred Skills and ExperienceExperience supporting executive offices, customer-facing environments, or high-visibility corporate spacesBackground in facilities coordination, workplace operations, or logistics coordinationExperience managing events, briefings, or customer visits in a professional settingFamiliarity with EHS processes, security protocols, or controlled-access environmentsExperience working in aerospace, defense, industrial, or similarly regulated organizationsExperience supporting small, high-performance teams in fast-growing companiesBudget tracking or light financial administration experienceStrong sense of ownership over physical space, logistics flow, and workplace experienceOther DutiesPlease 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 PerksAll 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 StatementEmployment 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.