Senior Information Technology System and Network Engineer

Job Summary

We are seeking a highly skilled Level 3 MSP Engineer to act as the final escalation point for complex infrastructure, cloud, security, networking, and unified communications issues. The ideal candidate will have deep hands-on experience with Cisco collaboration technologies, Microsoft 365, Azure AD, enterprise networking, firewalls, security platforms, and virtualization .

This role requires strong troubleshooting expertise, architectural understanding, and the ability to work independently in a fast-paced Managed Services or enterprise IT environment.

Key Responsibilities

Tier 3 Support & Escalations

• Act as the highest level of technical escalation for complex infrastructure, network, security, and UC issues.
• Perform deep root-cause analysis and provide permanent fixes for recurring problems.
• Work closely with L1/L2 teams, providing guidance, mentoring, and technical direction.

Unified Communications & Voice

• Administer, troubleshoot, and upgrade Cisco CUCM, UCCX, CUC , and related collaboration components.
• Manage Webex Calling , Cisco IP Phones, and Webex soft clients.
• Troubleshoot SIP call flows, call setup issues, and vendor interoperability problems.
• Use Wireshark to analyze packets, reconstruct calls, debug SIP sessions, and identify voice quality issues.
• Manage and upgrade 3CX PBX environments.

Microsoft 365 & Azure

• Administer Office 365 / Microsoft 365 tenants at scale.
• Perform Exchange On-Prem to O365 migrations .
• Handle GoDaddy Office 365 defederation and migration to full Microsoft 365 tenants.
• Develop and maintain PowerShell scripts for large-scale tenant administration and automation.
• Implement and manage Azure Enterprise Applications and SAML integrations (Meraki, Webex, etc.).
• Manage Azure AD (Entra ID) cloud-only and hybrid environments.
• Configure Azure AD Join , device policies, and identity integrations.
• Administer Azure Endpoint Management (Intune) for device and policy management.

Security & Identity

• Implement and manage DUO MFA and 2FA for VPNs (Meraki, Sophos, SonicWALL).
• Configure and support DUO RADIUS Authentication Proxy .
• Manage and troubleshoot SentinelOne endpoint protection.
• Implement secure authentication and access control across cloud and on-prem environments.

Networking & Firewalls

• Manage and troubleshoot:
• Cisco switches
• Meraki switches, Wi-Fi, and firewalls
• Cisco Firepower firewalls and Firepower Management Center
• Cisco ASA firewalls , including upgrades and migrations (SFR modules)
• Design, implement, and troubleshoot Site-to-Site VPNs .
• Perform Cisco Nexus switch upgrades, configuration, and lifecycle management.

Backup, Virtualization & Linux

• Design and manage backup and recovery solutions.
• Administer Linux systems , with a focus on immutable backups for VEEAM repositories .
• Manage VMware vSphere / ESXi environments, including implementation and upgrades.

Required Skills & Expertise

Core Technical Skills

• Cisco Collaboration (CUCM, UCCX, CUC, Webex)
• Microsoft 365 / Office 365
• Azure AD (Entra ID), Intune, Azure Enterprise Apps
• DUO MFA, VPN security, firewall authentication
• Cisco, Meraki, ASA, Firepower, Nexus networking
• SIP, VoIP, packet-level troubleshooting (Wireshark)
• PowerShell scripting
• VMware vSphere / ESXi
• Linux administration (backup-focused)
• SentinelOne
• 3CX PBX

Soft Skills

• Strong analytical and problem-solving mindset
• Excellent documentation and communication skills
• Ability to work independently on critical issues
• Experience mentoring L1/L2 engineers
• Customer-focused approach in high-pressure situations

Preferred Certifications (Nice to Have)

• CCNP / CCIE (Collaboration, Security, or Enterprise)
• Microsoft Azure Administrator / Architect
• VMware VCP
• Security certifications (DUO, SentinelOne, firewall vendors)