IT Security Senior Engineer

Donnelley Financial Solutions

4d•Remote

About The Position

The Senior Network Security Engineer provides advanced engineering expertise and technical leadership for enterprise network security across cloud and on-premises environments. The role leads complex designs and implementations, serves as a senior escalation point for major incidents, and advances modernization initiatives aligned with DFIN’s Zero Trust strategy. The engineer mentors others, shapes standards, and partners with stakeholders to deliver secure, scalable, and resilient network security platforms. The position encompasses secure architecture for LAN/WAN, hybrid cloud, and SaaS environments; enterprise firewall, WAF, DDoS, API security, and load-balancing capabilities; Azure connectivity and security controls; microsegmentation; telemetry and NDR integrations; and automation. The engineer also leads incident response and root-cause analysis, improves operational practices, and partners with platform engineering to incorporate secure connectivity into CI/CD and infrastructure-as-code workflows.

Requirements

7–10+ years of hands-on experience in network security engineering, including cloud networking and enterprise platforms.
Deep expertise in firewall and WAF policy architecture, routing, segmentation, and cloud networking controls.
Proven ability to lead complex troubleshooting and incident response for high-impact events.
Strong understanding of Zero Trust, defense-in-depth, and secure-by-design principles.
Experience designing operationally sustainable solutions, including documentation, runbooks, lifecycle management, and monitoring.
Ability to communicate complex architecture and risk decisions to technical and business stakeholders.
Demonstrated leadership through mentorship, technical reviews, and influence across teams.
High ownership, sound judgment, and ability to prioritize under pressure.

Nice To Haves

Bachelor’s degree in Computer Science, IT, or a related field, or equivalent experience.
CCNP/CCIE (Security or Enterprise) certification, or equivalent experience.
Cloud networking/security certifications, preferably Azure; AWS/GCP certifications are a plus.
SASE/SD-WAN certifications, such as Zscaler.

Responsibilities

Lead design of secure architectures for LAN/WAN, hybrid cloud, and SaaS environments and define reference patterns.
Own medium-to-large initiatives, such as segmentation, SASE expansions, and firewall modernization, from design through delivery.
Contribute to multi-year roadmaps by identifying gaps, reducing technical debt, and aligning work with Zero Trust outcomes.
Engineer and optimize firewall and WAF capabilities, DDoS protections, API security patterns, and load-balancing controls.
Design Azure connectivity and security controls at scale, including hub-and-spoke architectures, shared services, private connectivity, and routing strategies.
Implement and operationalize microsegmentation strategies and integrate them with identity and endpoint signals.
Lead integrations with telemetry and NDR tools to improve detection fidelity and end-to-end visibility.
Serve as Level 3 escalation for high-severity incidents, coordinate technical response, and ensure timely mitigation.
Lead root-cause analyses, author post-incident reports, and drive systemic fixes and resilience improvements.
Establish and improve runbooks, operational metrics, reliability practices, and on-call readiness for owned platforms.
Define automation standards for network and security workflows and 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.
Mentor engineers in architecture, troubleshooting, and secure design; provide technical reviews and guidance.
Present options, risks, and recommendations to stakeholders and partner with vendors to resolve complex issues.