Sr. Tier III O&M Engineer

The Digital Modernization Sector at Leidos is seeking aSr. Tier III operations and maintenance (O&M) engineer to support various WAN and LAN networks. Will provide incident resolution, routing changes, firewall changes; act as subject matter expert in WAN and LAN technologies; support intra- and inter- net and other data communications systems or segments of networked system.Description of Job Duties/Responsibilities:Support operations and maintenance activities and administer networks including LAN and WAN technologies such as OSPF, BGP, VRF’s, VLAN’s, VRRP, MPLS.Monitor the performance of systems and networksConfigure, and test hardware, networking software and operating system softwareReview user requests for upgrades or additions to the network to assess impact on network performance and provide advice and guidance on the most practical technical approach to meeting user requirementsPerform long term O&M activities to include tier 3 troubleshooting and problem resolutionPrepare troubleshooting procedures for restoring the network to optimal performance levelsProvide fault management for the network and supports performance management functionsRespond, isolate, and resolve network troublesExecute reporting functions and data input associated with network managementCoordinate with configuration management and implementation teamsAnalyze network characteristics (e.g., traffic, connect time, transmission speeds, packet sizes, and throughput); recommend procurement, removals, and modifications to network componentsOptimize network topologies and site configurations.Coordinate requirements with usersAssess and document current site network configuration and user requirementsMaintain operating systems, communications software, data base packages, compilers, assemblers, and utility programsApply software, hardware, and standards information technology skills in the analysis, specification, development, integration, and acquisition of open systems for Information Management (IM) applicationsEnsure these systems and applications are compliant with standards for open systems architectures, reference models, and profiles of standards - such as the IEEE Open Systems Environment (OSE) reference model - as they apply to the implementation and specification of IM solutions on the application platform, across the application program interface (API), and the external environment/software applicationMay have up to 10% COMSEC responsibilities, as needed.Subject to be called in during afterhours for incident resolution.RequirementsTS SCI with a PolyCandidate must have 16 years of experience that can be a combination of work history and education. This equates to a Doctorate and 8 years, master’s and 10 years, bachelor’s and 12 years, associates and 14 years or HS diploma and 16 years.Must comply with DoD 8570 Information Assurance Technical (IAT) Level 2.Experience in configuring and troubleshooting boundary protection technologies such as Palo Alto, Cisco ASA, and Forcepoint appliancesExperience with configuring and troubleshooting Juniper and Cisco routers and switches.Experience with protocols such as OSPF, BGP, VPN’s, VRF’s, MPLS.Working knowledge of boundary protection best practicesUnderstanding of routing, switching, Internet Protocol (IP) subnet, Network Address Translation (NAT) and security technologiesDemonstrated ability to engineer and modify rulesets to allow connectivity for new customer requirementsDemonstrated ability to read, understand, and develop schematic diagrams, technical manuals, and documentation such that the supported equipment and software can be maintained with minimal trainingWorking knowledge of Service Now or similar IT Service Management (ITSM) productsSuperior verbal and written communication skillsIntermediate-level knowledge of MS Office products Word, Excel, PowerPoint, and VisioIf you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.Original Posting:June 30, 2026For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.Pay Range:Pay Range $92,300.00 - $166,850.00The Leidos pay range for this job level is a general guideline onlyand not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.SummaryLocation: Aurora, COType: Full time