We are seeking a highly skilled Senior Information Security Engineer to join our IT Security organization in Worcester, MA or in a remote capacity.POSITION SUMMARY:The Senior Security Engineer is a technical leader responsible for the design, implementation, operation, automation, and continuous improvement of enterprise security infrastructure services. This role serves as the subject matter expert for Public Key Infrastructure (PKI), certificate lifecycle management, firewalls, web proxy services, Linux-based security platforms, and network security operations. The individual will lead strategic initiatives, provide advanced troubleshooting support, develop automation solutions, and partner with infrastructure, networking, cloud, and application teams to ensure secure and resilient enterprise services. This is a full-time, exempt position.IN THIS ROLE, YOU WILL: Lead the design, implementation, administration, and optimization of enterprise PKI and certificate management services, ensuring availability, scalability, and compliance with security standards.Own the certificate lifecycle management process, including issuance, renewal, revocation, discovery, monitoring, and remediation of expiring certificates across on-premises and cloud environments.Serve as the technical lead for Firewall services, including architecture, policy management, rule reviews, segmentation strategies, and security hardening.Manage and support enterprise Web Proxy solutions, including policy development, URL filtering, SSL/TLS inspection, access controls, and threat protection capabilities.Provide advanced network and security troubleshooting expertise, identifying and resolving complex connectivity, authentication, routing, DNS, TLS, and application communication issues.Partner with Network Engineering teams to design secure network architectures and implement security controls that align with business and regulatory requirements.Develop and maintain automation solutions using scripting and programming languages such as Python, Bash, PowerShell, or similar technologies to improve operational efficiency and reduce manual processes.Create automated monitoring, alerting, and remediation workflows for security infrastructure platforms and services.Administer and support Linux-based security platforms, ensuring system performance, hardening, patching, vulnerability remediation, and operational stability.Lead security infrastructure projects from planning through implementation, coordinating activities across multiple technical teams and stakeholders.Perform security assessments and configuration reviews to identify risks, vulnerabilities, and opportunities for service improvement.Develop and maintain technical standards, operational procedures, and architecture documentation for PKI, firewalls, proxy services, and Linux environments.Support incident response activities by providing deep technical expertise during security investigations, service outages, and cyber events.Evaluate emerging technologies and security solutions, making recommendations to improve the organization's security posture and operational effectiveness.Implement and maintain security controls supporting regulatory, audit, and compliance requirements.Provide technical leadership and mentorship to junior engineers and operations personnel, promoting best practices and knowledge sharing.Collaborate with cloud, infrastructure, and application teams to integrate security services into enterprise and cloud-native environments.Participate in on-call rotations and escalation support, serving as a senior resource for critical security and infrastructure incidents. WHAT YOU NEED TO APPLY: Bachelor's degree in Information Technology, Computer Science, Cybersecurity, Engineering, or equivalent experience.7+ years of experience in Information Security, Network Security, or Infrastructure Engineering roles.Demonstrated expertise in PKI, Certificate Authorities (CA), certificate lifecycle management, and TLS/SSL technologies.Extensive hands-on experience managing enterprise firewall platforms (e.g., Palo Alto, Check Point, Cisco Firepower, Fortinet, or similar).Strong experience supporting Web Proxy technologies such as Zscaler, Blue Coat/Symantec ProxySG, Netskope, or similar platforms.Advanced knowledge of TCP/IP networking, routing, switching, DNS, DHCP, VPNs, load balancing, and network security architecture.Strong expertise with Linux operating systems, including system administration, troubleshooting, performance tuning, and security hardening.Demonstrated experience developing automation using Python, Bash, PowerShell, Ansible, Terraform, or similar technologies.Experience with security monitoring, logging, and event analysis tools.Strong understanding of authentication and authorization technologies including LDAP, Active Directory, Kerberos, SAML, OAuth, and certificate-based authentication.Proven ability to troubleshoot complex, multi-tier application and network issues. Excellent written, verbal, and interpersonal communication skills.Authorization to work in the United States without current or future sponsorship (U.S. citizen or lawful permanent resident). BONUS POINTS FOR: Industry certifications such as CISSP, GIAC, Security+, CCNP Security, PCNSE, AWS Security Specialty, or equivalent.Experience with cloud security platforms including Microsoft Azure, AWS, and Google Cloud.Knowledge of Infrastructure as Code (IaC) and DevSecOps practices.Experience with enterprise vulnerability management and security compliance programs.Familiarity with container technologies, Kubernetes, and cloud-native security architectures.