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 ExpressRoute, 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.

Required Qualifications

• 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 (ExpressRoute, 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).

Preferred / Nice to Have

• 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.