Sr. Network Systems Engineer, Firewall

McKesson•Mississauga, ON

6d•$99,100 - $132,100•Hybrid

About The Position

McKesson is seeking a Senior Network Security Engineer to help design, secure, and evolve our global enterprise network infrastructure. This role serves as a strategic technical leader responsible for building resilient, scalable, and secure network architectures that support business growth, regulatory compliance, and digital transformation initiatives. The ideal candidate brings deep expertise in network security architecture, Zero Trust principles, firewall technologies, and enterprise networking. You will partner closely with Security, Infrastructure, Cloud, and Enterprise Architecture teams to strengthen McKesson's security posture while enabling reliable connectivity across hybrid environments.

Requirements

7+ years of professional experience in network engineering, network security, or security architecture roles.
Bachelor's degree in Computer Science, Information Technology, Cybersecurity, or equivalent experience.
Experience designing and implementing enterprise network security architectures.
Expertise with Palo Alto firewalls, policy management, and security controls.
Experience with Zero Trust Architecture, network segmentation, and secure network design.
Strong understanding of routing, switching, TCP/IP, BGP, OSPF, SD-WAN, and enterprise networking technologies.
Experience with VPN technologies, ZTNA, NAC, or secure remote access solutions.
Experience supporting security monitoring tools including IDS/IPS, network traffic analysis, or security analytics platforms.

Nice To Haves

Experience with Zscaler, HPE Aruba EdgeConnect, SASE, or Secure Internet Gateway technologies.
Experience securing hybrid cloud environments.
Knowledge of regulatory, compliance, and risk management frameworks.
Experience with automation tools such as Ansible, Python, or infrastructure-as-code solutions.
Experience conducting security architecture reviews and risk assessments.
Exposure to large-scale global enterprise environments.
Industry certifications such as PCNSE, CCNP Security, CCIE, CISSP, or equivalent.
Experience collaborating with enterprise architecture and cybersecurity leadership teams.

Responsibilities

Design and implement secure enterprise network architectures across hybrid cloud and on-premises environments.
Develop and lead Zero Trust Architecture initiatives, including network segmentation and micro-segmentation strategies.
Conduct security architecture reviews and provide recommendations that reduce risk and strengthen resilience.
Engineer and optimize firewall and perimeter security solutions, including Palo Alto technologies.
Support secure connectivity through Zscaler, HPE Aruba EdgeConnect, Secure Internet Gateway, and web proxy solutions.
Design and govern secure remote access solutions leveraging ZTNA, VPN, and Network Access Control (NAC).
Monitor, analyze, and improve network security through IDS/IPS technologies, traffic analysis, and security analytics platforms.
Lead troubleshooting, root cause analysis, and remediation efforts for complex network and security incidents.