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 Power Shell scripts for large-scale tenant administration and automation.
- Implement and manage Azure Enterprise Applications and SAML integrations (Meraki, Webex, etc.).
- Manage Azure AD (Entra ) – 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, Sonic

WALL).
- Configure and support DUO RADIUS Authentication Proxy.
- Manage and troubleshoot Sentinel One 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 ), Intune, Azure Enterprise Apps
- DUO MFA, VPN security, firewall authentication
- Cisco, Meraki, ASA, Firepower, Nexus networking
- SIP, VoIP, packet-level troubleshooting (Wireshark)
- Power Shell scripting
- VMware vSphere / ESXi
- Linux administration (backup-focused)
- Sentinel One
- 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, Sentinel One, firewall vendors)