IT Security Senior Engineer at Donnelley Financial Solutions

Job description

Join a dynamic team at the pulse of global markets, where we deliver innovative software and service solutions for essential financial reporting and capital markets transactions. At DFIN, we are a values-driven organization that empowers you to build a fulfilling career while bringing your authentic self to work every day. Our “Win as One” mentality ensures that our team’s success is directly linked to Client, Shareholder and Employee Satisfaction. In 2026, DFIN was named #1 on the 2026 Top 100 Global Most Loved Workplaces® by Best Practice Institute. We have also been recognized as one of America’s Most Loved Workplaces® for five consecutive years and a Built In Best Place to Work for six years, reflecting our continued commitment to supporting employees’ total well-being. Enjoy competitive compensation, a flexible workplace, comprehensive benefits, and opportunities for professional growth. Bring your passion and talents to DFIN – because being YOU thrives here. Summary: The Senior Network Security Engineer provides advanced engineering expertise and technical leadership for enterprise network security across cloud and on-prem environments. This role leads complex designs and implementations, serves as a senior escalation point for major incidents, and drives modernization initiatives aligned to DFIN’s Zero Trust strategy. The senior engineer mentors other engineers, shapes standards, and partners with stakeholders to deliver secure, scalable, and resilient network security platforms. Responsibilities: Architecture, Design & Roadmap Leadership Lead the design of secure architectures for LAN/WAN, hybrid cloud, and SaaS environments; define reference patterns. Own medium-to-large initiatives (e.g., segmentation, SASE expansions, firewall modernization) from design through delivery. Contribute to multi-year roadmaps by identifying gaps, reducing technical debt, and aligning to Zero Trust outcomes. Advanced Network Security Engineering Engineer and optimize advanced firewall/WAF capabilities, DDoS protections, API security patterns, and load balancing controls. Design Azure connectivity and security controls at scale (hub/spoke, shared services, private connectivity, routing strategy). Implement and operationalize microsegmentation strategies and integrate with identity and endpoint signals. Lead integrations with telemetry and NDR tools to improve detection fidelity and end-to-end visibility. Operational Excellence & Incident Leadership Act as Level 3 escalation for high-severity incidents; coordinate technical response and ensure timely mitigation. Lead root-cause analysis, author post-incident reports, and drive systemic fixes and resilience improvements. Establish and improve runbooks, operational metrics, and reliability practices for owned platforms; guide on-call readiness. Additional Responsibilities DevSecOps & Automation (Technical Lead) Define automation standards for network/security workflows; build reusable modules and guardrails for safe changes. Partner with platform engineering to embed secure connectivity controls into CI/CD and infrastructure-as-code pipelines. Mentorship & Cross-Functional Leadership Mentor engineers in architecture, troubleshooting, and secure design; provide technical reviews and guidance. Influence stakeholders by presenting options, risks, and recommendations; partner with vendors to resolve complex issues. Technology & Domain Exposure Enterprise firewalls (on-prem and cloud), WAF, DDoS protection, API security, and load balancing Microsegmentation/segmentation design and enforcement; Zero Trust access patterns (ZTNA) SASE/SSE and SD-WAN architectures; identity-integrated access and policy strategies Azure network architecture at scale (hub/spoke, routing, private endpoints, shared services, resiliency patterns) Telemetry, logging, SIEM integrations, and NDR tool integrations to improve detection and response Advanced automation/scripting (Python/PowerShell), CI/CD, and infrastructure-as-