Lead Infrastructure Engineer

Key Responsibilities

• Mainframe modernization enablement
  • Partner with application and platform teams to migrate and modernize mainframe-adjacent workloads (e.g., rehost/refactor components, distributed integrations, data movement patterns).
  • Design target-state infrastructure and transition architectures for Azure, including landing zones and platform services alignment.
• Azure infrastructure engineering
  • Build and operate Azure core services: VNETs/subnets, routing, NSGs, Azure Firewall, Private Link, DNS, identity integrations, and resource organization (subscriptions, management groups, tagging).
  • Implement Infrastructure as Code (IaC) using Terraform/Bicep and integrate with CI/CD pipelines.
• Hybrid connectivity & network performance
  • Design, implement, and troubleshoot on-prem Azure connectivity using
    Express Route
    , VPN, Virtual WAN, and hub/spoke (or vWAN) architectures.
  • Configure and validate routing (BGP), MTU/MSS settings, latency/throughput baselines, and failover behavior.
  • Tune connectivity performance for critical flows (batch, file transfer, API, messaging, data replication), including bandwidth planning and QoS considerations where applicable.
• Performance tuning & reliability
  • Identify and remediate bottlenecks across network, compute, storage, and platform services (e.g., VM sizing, disk throughput/IOPS, load balancing behavior, TCP tuning, connection pooling implications).
  • Establish monitoring/observability (Azure Monitor, Log Analytics, Network Watcher, Application Insights where relevant), SLOs, alerting, and runbooks.
  • Lead root cause analysis for performance incidents and drive preventative improvements.
• Security, governance, and operational excellence
  • Apply cloud security best practices (least privilege, segmentation, private endpoints, key management) and ensure alignment with governance controls.
  • Produce clear design documentation, operational procedures, and knowledge transfer.

• 10+ years in infrastructure engineering (cloud and/or datacenter), with
  direct experience supporting modernization or migration from mainframe environments
  to distributed/cloud platforms.
• Strong, practical experience with
  Microsoft Azure
  , especially:
  • Networking (VNET, routing, NSG, Azure Firewall, Private Link, DNS)
  • Connectivity (Express Route, VPN, vWAN, hub/spoke)
  • Compute/storage fundamentals (VMs, disk performance, availability patterns)
• Demonstrated ability to
  set up, troubleshoot, and performance-tune hybrid connectivity
  (latency, throughput, packet loss, MTU/MSS, routing, failover).
• Infrastructure as Code experience (Terraform and/or Bicep/ARM) and Git-based workflows.
• Strong troubleshooting skills and ability to work across teams (network, security, app, data).

• Experience with modernization patterns: rehost, replatform, refactor; familiarity with integration with mainframe systems (e.g., batch scheduling, file transfer, messaging, data replication).
• Azure Landing Zone / CAF experience, policy/guardrails, and enterprise subscription design.
• Experience with performance tools and methods (load testing coordination, network path analysis, packet capture interpretation, baseline/SLO definition).
• Containers (AKS), API management, and/or messaging services (Service Bus, Event Hubs) exposure.