Become an integral part of a diverse team while working at an Industry Leading Organization, where our employees come first. At ManTech International, you’ll help protect our national security while working on innovative projects that offer opportunities for advancement. Currently, ManTech is seeking a motivated, career and customer-oriented **Computer Systems** **Engineer/Architect** to join our team supporting a large U. S. Government program within the National Capitol Region. **Responsibilities include, but are not limited to:** + Submit change requests and troubleshoot as requested by components, the Justice Security Operations Center (JSOC), and others: forward proxy, reverse proxy, DNS, SSLV, and firewall requests to AT&T via Business Direct for implementation by AT&T. + Manage high-volume (more than 1M messages per day) SMTP relays. + Manage the Proofpoint mail security system. + Diagnose mail delivery issues through several layers of security. + Monitor and manage mail routing using an LDAP directory. + Diagnose user connectivity issues using logs. + Work with partner entities providing in-depth IT investigations. + Work with partner entities modifying policies on IT systems. + Monitor and manage Infoblox DNS system as well as general BIND/DNS functionality. + Utilize the Xymon monitoring system to evaluate any potential issues and investigate any problems. + Configure Xymon and creating new monitoring modules. + Perform Dynatrace and SNMP-based monitoring. + Maintain archival logging for network systems. + Implement a Zscaler Zero Trust solution for TIC 3.0 deployment. + Manage IP Address allocations with IPAM + Administer and manage Unix/Linux operating systems. **Basic Qualifications:** + A bachelor’s degree in computer science or management information systems or equivalent discipline + A minimum of (7) seven years of experience in a related technical environment. + Direct experience configuring and troubleshooting forward and reverse proxies and network firewalls + Experience with the design, installation, maintenance, and coordination of the use of the network system. + Experience evaluating complex hardware and software and peripheral equipment for large, complex networks. + Proven experience managing network performance. + Experience troubleshooting and resolving complex problems to ensure quality transmission service on the network. + Experience managing, maintaining, creating, and deleting user accounts as well as maintaining and updating system security plans on all platforms. + Proven experience implementing and managing network policies, procedures, and standards. **Security Clearance Requirements:** + Must be a U.S. citizen + Must have an active Top-Secret **Physical Requirements:** + Must be able to be in a stationary position more than 50% of the time + Must be able to communicate, converse, and exchange information with peers and senior personnel + Constantly operates a computer and other office productivity machinery, such as a computer + The person in this position frequently communicates with co-workers, management, and customers, which may involve delivering presentations. Must be able to exchange accurate information in these situations + The person in this position needs to occasionally move about inside the office to access file cabinets, office machinery, etc.