Requisition Number: 2354271 * - Undergraduate degree or equivalent experience. * Careers with Optum. Here's the idea. We built an entire organization around one giant objective; make the health system work better for everyone. So when it comes to how we use the world's large accumulation of health-related information, or guide health and lifestyle choices or manage pharmacy benefits for millions, our first goal is to leap beyond the status quo and uncover new ways to serve. Optum, part of the UnitedHealth Group family of businesses, brings together some of the greatest minds and most advanced ideas on where health care has to go in order to reach its fullest potential. For you, that means working on high performance teams against sophisticated challenges that matter. Optum, incredible ideas in one incredible company and a singular opportunity to do your life's best work. SM Diversity creates a healthier atmosphere: UnitedHealth Group is an Equal Employment Opportunity/Affirmative Action employer and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, age, national origin, protected veteran status, disability status, sexual orientation, gender identity or expression, marital status, genetic information, or any other characteristic protected by law. UnitedHealth Group is a drug-free workplace. Candidates are required to pass a drug test before beginning employment.

• Develop and maintain a multi-platform implant written in Rust (Windows, Linux, macOS; x86/x64/ARM) • Build and extend C2 server infrastructure, task dispatch, and communications protocols • Implement post-exploitation modules: credential access, process injection, privilege escalation, lateral movement • Research and implement AV/EDR evasion techniques to keep tooling operational against modern defenses • Design and build network pivoting and tunneling capabilities • Write integration tests that exercise tooling against real targets across multiple OS and architecture combinations

The NASA IT portfolio with Digital Modernization Sector currently has an opening for a RHEL Engineer-Mailflow to manage and maintain our Red Hat Enterprise Linux (RHEL) servers and M365 collaboration services as well as supporting enterprise email services. Must have enterprise mailflow experience. This is a telework position, but the ideal candidate will reside within reasonable commute distance from a NASA operating center (Johnson Space Center (Houston, TX) or Marshall Space Flight Center (Huntsville, AL)). This is an exciting opportunity to use your experience helping the NASA End-User Services and Technologies (NEST) mission. In this mission, we serve as an agile, trusted partner to transform, integrate, simplify, modernize, and safeguard NASA IT systems and data. And, above all else, continuously enhance the end-user experience. The RHEL Engineer is responsible for supporting and enhancing the mail flow environment at NASA to include M365 and on-premises infrastructure. This infrastructure includes Red Hat Enterprise Linux-based Postfix servers, Exchange Server SE, Exchange Online, Microsoft Teams, Microsoft Defender and the M365 Security Suite, SMTP gateways, email authentication standards (SPF, DKIM, and DMARC), and ensuring high availability through multi-site load balancing and system hardening. Having a strong technical background in these technologies will be key for the successful candidate. The ideal candidate will have deep technical expertise in Linux systems, email security, and automation. Must be able to clearly articulate technical dialog with a variety of audiences to include NEST and NASA management. Key Responsibilities - Email Security & Authentication: - Implement and monitor SPF, DKIM, and DMARC policies. - Troubleshoot email delivery issues and enforce anti-spoofing measures. - Linux Server Administration: - Full lifecycle management of our Red Hat servers, including installation, configuration and patching in production and test environments. - Perform security patching, upgrades, and hardening to meet compliance standards and remediate critical vulnerabilities - Email Infrastructure Management: - Configure and maintain Postfix SMTP servers for enterprise email flow. - Integrate email services with DNS, LDAP, and TLS for secure delivery. - Load Balancing & High Availability: - Knowledge of load balancers and DNS for email services. - Support failover and disaster recovery strategies. - Monitoring & Troubleshooting: - Use tools like Grafana, Nagios, Zabbix, or similar for system and service monitoring. - Analyze logs and resolve complex SMTP and network issues. - Automation & Scripting: - Automate routine tasks using Bash, Python, PowerShell, and configuration management tools (Ansible, Puppet). - Maintain accurate documentation of configurations and processes. - Microsoft 365 Tenant Management: - Deliver, support, and enhance M365 services in Exchange Online, Exchange Online Protection, retention policies, litigation holds, etc - Introduce new and modify existing M365 mail flow features and services across NASA and support customer issues Required Technical Skills - Advanced proficiency in Red Hat Enterprise Linux (RHEL 8/9) Bash administration. - Advanced proficiency in Hybrid Exchange and the M365 collaboration stack - Expertise in Postfix SMTP configuration, troubleshooting, and mailflow - Expertise in SPF, DKIM, DMARC implementation, troubleshooting, and monitoring. - Familiarity with load balancers (NGINX, HAProxy) and reverse proxy setups. - Solid understanding of DNS, TCP/IP, LDAP, and secure email transport (TLS/SSL). - Scripting skills in Bash or Python and PowerShell. - Experience with automation tools (Ansible, Puppet). - Knowledge of system monitoring tools and performance tuning. Qualifications - Must be a US citizen to apply - Must be able to obtain a Public Trust or currently possess a security clearance to be considered - Bachelor’s degree in Computer Science, Information Technology, or equivalent experience. - 8-12 years of relevant experience - Experience with SMTP management including configuration, security, and troubleshooting - Hands-on experience in command-line Linux system administration - Experience as service owner within an enterprise or GCC M365 environment - Red Hat certifications (RHCSA, RHCE) strongly preferred. If 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: April 6, 2026 For 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 - $166,850.00 The Leidos pay range for this job level is a general guideline only and 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.

With a company culture rooted in collaboration, expertise and innovation, we aim to promote progress and inspire our clients, employees, investors and communities to achieve their greatest potential. Our work is the catalyst that helps others achieve their goals. In short, We Enable Possibility℠. The Director, Multi Line Account Engineer will be responsible for providing in depth portfolio management of a dedicated UW team (5-10 underwriters). This is for all lines (property, general liability, workers compensation and auto) and would involve: Responsibilities: - Perform account management functions for assigned service accounts collaborating with underwriting, claims, policy holders and brokers. Focus on reducing loss potential while developing healthy account relationships to drive account retention and partnership. - Complete on-site and remote surveys to assess an account’s operations, exposures, and hazard mitigation strategies to help Arch underwriting best identify and retain profitable business. - Generate and review required reports and recommendations. Meet reporting deadlines in accordance with departmental performance objectives. - Manage workload with use of 3rd parties as needed to accomplish assigned work by the deadlines of underwriters and department. This includes ensuring the quality of work provided by the 3rd parties. - Assist Arch and clients with ongoing and specific projects. Support technical training presentations for internal and external clients as required/appropriate. - Strong analytical and decision skills. Ability to utilize tools/software to create and modify documents as well as data analysis for account and book improvement. Required Skills: - Minimum 5 years of risk control experience with both account management and site/field surveys. Solid knowledge base and professional experience in the following areas: property, general liability, products liability, workers compensation, auto, and excess. - Knowledge of NFPA, FM, OSHA, DOT and other relevant standards and best practices. - Demonstrated knowledge of Microsoft Office Suite applications. - Phenomenal verbal and written communication skills and business acumen. - Continued learning and application of new concepts to your role. Education: - Bachelor's Degree in an engineering or safety related field with relevant insurance industry experience taken into consideration. - Industry designations appreciated but not required. #LI-JD1 #LI-Remote Arch is committed to helping employees succeed through our comprehensive benefits package that includes multiple medical plans plus dental, vision and prescription drug coverage; a competitive 401k with generous matching; PTO beginning at 20 days per year; up to 12 paid company holidays per year plus 2 paid days of Volunteer Time Offer; basic Life and AD&D Insurance as well as Short and Long-Term Disability; Paid Parental Leave of up to 10 weeks; Student Loan Assistance and Tuition Reimbursement, Backup Child and Elder Care; and more. Click here to learn more on available benefits. Do you like solving complex business problems, working with talented colleagues and have an innovative mindset? Arch may be a great fit for you. If this job isn’t the right fit but you’re interested in working for Arch, create a job alert! Simply create an account and opt in to receive emails when we have job openings that meet your criteria. Join our talent community to share your preferences directly with Arch’s Talent Acquisition team. 14400 Arch Insurance Group Inc.