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 form  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)