Enterprise Solutions and Management (ESM) is a rapidly growing government contractor that provides strategic IT services that meet mission needs for Defense and Federal customers. We are hiring a System Administrator- Senior to support an enterprise-level program within a federal environment.Job Description and ResponsibilitiesThe Senior System Administrator ensures stable, secure, and efficient operation of critical IT infrastructure, including servers, networks, storage, applications, and communication links across multiple locations. Responsibilities include planning, installing, configuring, maintaining, upgrading, and optimizing systems; troubleshooting software, connectivity, and performance issues; and conducting capacity and vulnerability management. Ensures compliance with STIGs and RMF requirements and applies advanced technical expertise in Active Directory, VMware, Linux, Windows, application networking, load balancing, and fault-tolerant architectures. Improves operational efficiency through automation, scripting, and standardized procedures; provides system administrator and end-user training; and develops recommendations for technology improvements aligned with business and mission objectives. Provides local and remote support, leads system administrators in day-to-day operations, and provides senior-level troubleshooting, mentorship, documentation, patching, and incident response to maintain system availability and mission readiness.Required Knowledge, Skills and Abilities (KSA)Knowledge of server, storage, network, and virtualization technologies, including Active Directory (AD), DNS, DHCP, Group Policy (GPO), and VMware.Ability to maintain system availability, performance, and security through monitoring, patching, vulnerability remediation, firewall management, and compliance with DoD STIGs and RMF requirements.Skill in developing technical documentation, SOPs, network diagrams, and system images, as well as automating administrative tasks using PowerShell, Python, Ansible, or similar scripting tools.Ability to diagnose and resolve complex system and network issues and provide advanced Tier 2/3 technical support, including backup, recovery, and disaster recovery operations.Skill in documenting and communicating system status, incidents, outages, and corrective actions through formal technical reports and briefings.Ability to assess infrastructure requirements, recommend technology improvements, and collaborate effectively with technical teams and military and civilian stakeholders.Desired KSABe a positive, self-motivated, and proactive person with the ability to adapt to change and tolerate stressful situationsCandidate must communicate effectively with team members, team lead, management, and government customersMust have the ability and desire to research and develop creative solutions to unique problems with minimal supervisionMinimum Training, Education, and CertificationsMinimum of five (5) years of experience as a System Administrator in a Microsoft Windows operating system environment.Minimum of ten (10) years of specialized Information Technology experience, including at least four (4) years of hands-on experience installing, configuring, maintaining, and troubleshooting a variety of hardware and software solutions.Minimum of three (3) years of experience configuring and managing IBM MQ.Minimum of three (3) years of experience configuring and managing Windows Internet Information Services (IIS).Must hold a minimum Bachelor's degree of Computer Science or other relevant field of studyDOD 8140 baseline certification - IAT Level IIMicrosoft Windows Server Hybrid Administrator Associate credential IBM MQ v9.4 Administrator - Professional or newer certificate Minimum Clearance Top SecretPhysical RequirementsRequired to stand, walk and sit; communicate verbally both in person and by telephone; use hands to finger, handle or feel objects or controls; reach with hands and arms. Regularly required to stoop, kneel, bend, crouch and lift up to 25 pounds. Specific vision abilities required by this job include close vision, distance vision, depth perception, color vision and the ability to adjust focus.Physical demands associated with this position include extensive walking (including stairs) throughout offices and between buildings. May require use of public transportation, personal or Government vehicle to drive to local and/or remote office locations.Additional RequirementsOther duties as assignedESM provides equal employment opportunity to all individuals regardless of race, color, creed, religion, gender, age, sexual orientation, national origin or ancestry, disability, genetic information, veteran status, gender identification or any other characteristic protected by state, federal or local law.