Network Transition Lead

Role: Network Transition Lead

Role Overview

The Senior L3 Network Transition Lead is responsible for advanced architecture support, escalation-level troubleshooting, and optimization of the customer’s Data Center network and Azure cloud networking environment. This role serves as the SME for routing, switching, data center fabrics, security integration, and cloud connectivity, ensuring end-to-end resilience and performance across hybrid infrastructure. The specialist will play a critical role during transition (discovery, architecture validation, onboarding) and provide L3 support during BAU for complex issues and changes.

Key Responsibilities

Data Center Networking (Primary Scope):

  • Lead deep-dive architecture reviews and troubleshooting for Datacenter involving Juniper and Cisco routing/switching environments.
  • Manage and optimize Nexus-based switching environments and data center connectivity paths.
  • Validate and enhance DCI links (Layer 2/Layer 3 connectivity between DCs).
  • Review and optimize network segmentation, VLAN architecture, routing distribution, and resiliency mechanisms.
  • Assess EOL/EOS hardware, firmware levels, and align with OEM best practices.
  • Supporting DC migrations, expansions, and major upgrades.

Cloud Networking – Azure (Primary Scope):

  • Own the architecture and troubleshooting of Azure VNets, subnets, NSGs, UDRs, and hub-spoke networks.
  • Manage hybrid connectivity:
  • ExpressRoute
  • BGP peering
  • IPSec/Site-to-Site VPN
  • Virtual Network Gateways
  • Validate routing flows across cloud–DC–branch paths.
  • Support Azure Firewall/third-party virtual firewall implementations.
  • Optimize cloud network security posture and routing boundaries.
  • Participate in critical incidents impacting cloud access or hybrid workloads.

Transition Phase Responsibilities:

  • Lead discovery and documentation for DC & cloud networking components.
  • Assess existing hybrid architecture and identify gaps, risks, and optimization areas.
  • Support integration of DC/cloud assets into MSP monitoring and ITSM workflows.
  • Provide design guidance for segmentation, routing, firewalling, and redundancy.
  • Prepare architecture/runbooks for L1/L2 teams.

BAU Support Responsibilities:

  • Serve as the highest-level escalation point (L3) for DC + cloud networking issues.
  • Act as the technical lead during transition, working closely with project managers and service delivery teams.
  • Communicate status, issues, and readiness assessments to internal and external stakeholders.
  • Ensure all contractual and operational requirements are met during the transition process.
  • Lead RCA and problem management for recurring or complex network issues.
  • Drive standardization and adopt golden configuration templates.
  • Mentor L1/L2 teams for skill uplift.
  • Participate in major/complex change implementations.

Technical Expertise

Primary Skills:

  • DC routing & switching (Cisco Nexus, Juniper EX/QFX preferred)
  • Layer 2/Layer 3 architectures, spanning-tree, VXLAN/EVPN (preferred), DCI
  • Azure networking: VNets, NSGs, UDRs, VNet peering, VPN GW, ExpressRoute
  • BGP, OSPF, route redistribution, segmentation
  • Hybrid connectivity and security alignment

Secondary Skills

  • Understanding of firewall integrations (Palo Alto, ASA, Azure Firewall)
  • Network security best practices & compliance checks.
  • Azure Load Balancer, F5 or equivalent load balancing technologies.
  • Monitoring & logging (PRTG, SolarWinds, Azure Monitor, Panorama)
  • Basic automation (Terraform, Ansible, PowerShell)
  • ITIL processes (Change/Incident/Problem)

Process Skills:

  • Strong knowledge of ITIL-based Service Transition processes.
  • Expertise in network discovery, assessment, and readiness validation.
  • Ability to produce clear technical documentation (as-built, SOPs, diagrams).
  • Skilled in risk/gap analysis and defining remediation actions.
  • Experience coordinating with cross-functional teams during onboarding.
  • Solid understanding of change management and operational handover.

Behavioral Skills :

  • Strong analytical thinking and problem-solving ability in complex technical environments.
  • Excellent communication and presentation skills across technical and business audiences.
  • Demonstrated leadership in project execution and mentoring of junior network engineers.
  • High degree of ownership, accountability, and attention to detail.
  • Flexible and adaptive to changing business needs and technologies.
  • Collaborative and team-oriented, fostering cross-functional partnerships.

Qualification:

  • Bachelor’s degree in computer science, Engineering, IT, or equivalent experience.
  • 7–12 years total experience in enterprise networking with at least:
  • 4+ years in Data Center networking (Cisco Nexus, Juniper QFX/EX, fabric technologies)
  • 2+ years in Azure cloud networking in production environments
  • Strong hands-on background with hybrid network architectures.
  • Experience in large-scale distributed environments and mission-critical data center networks.
  • Relevant certifications preferred: CCNP, JNCIS/JNCIP, PCNSE, Azure Network Engineer Associate, Meraki CMNA/CMNP.

Job Details

Company
Mphasis
Location
London, UK
Hybrid / Remote Options
Posted