Senior IT Infrastructure Engineer (network) in London

Senior IT Infrastructure Engineer (network) in London

London Full-Time No working from home possible
Colt Technology Services

Job ID - 36501

Function - DIO

Job location - Gurgaon/Bangalore

Job Type - Permanent

Why we need this role

We are seeking a Senior IT Infrastructure Engineer (Network) to act as a technical Subject Matter Expert (SME) across enterprise network services, supporting office, data centre, and hybrid cloud networking environments.

This is a hands-on engineering role focused on delivering resilient, secure-by-design, and high-performance network platforms using predominantly Cisco technologies, with exposure to Juniper and cloud-native networking. The role will be critical in ensuring network segmentation, security, and scalability across the organisation’s global infrastructure

What you will do

Act as a technical SME for network infrastructure, including:

Office / campus networks, Data centre networking, Hybrid cloud connectivity (Azure, GCP)

Design, implement, and support secure, scalable network solutions across:

LAN / WAN / Data Centre / Cloud

Own and optimise Cisco-based network platforms, including:

Routing and switching, Cisco ACI (Application Centric Infrastructure), Policy-driven segmentation

Support and manage F5 load balancing platforms, including:

LTM configuration and optimisation, Traffic management and application delivery, High availability and failover design

Deliver secure-by-design network architecture, including:

Network segmentation and micro-segmentation, Zero Trust principles, Alignment to enterprise security controls

Design and support hybrid networking solutions, including:

Connectivity to Azure and GCP

VPN and private connectivity models (e.g. ExpressRoute, Interconnect)

Troubleshoot and resolve complex network incidents and performance issues across multi-layer environments

Drive network automation and standardisation to improve operational efficiency

Produce and maintain high-quality network documentation, including:

High-level and low-level designs, Network diagrams, Runbooks and operational procedures, Configuration standards

Collaborate with:

Security teams (segmentation, network security controls)

Cloud engineering teams

Platform and infrastructure teams

Participate in the on-call rota to support critical network incidents

What we're looking for

Required Skills & Experience

Strong hands-on experience with:

Cisco networking technologies (core requirement)

Data centre networking and Cisco ACI

F5 load balancing platforms

Experience with:

Juniper networking technologies (desirable)

Hybrid cloud networking (Azure and/or GCP)

Deep knowledge of:

Network segmentation and secure network design

Routing and switching protocols (e.g. BGP, OSPF)

Layer 4–7 load balancing concepts

High availability and resilient design

Proven ability to design, implement, and support enterprise-scale network environments

Strong troubleshooting experience across:

LAN

WAN

Data centre fabric

Hybrid cloud connectivity

Shape

✅ Technical Competencies

Recognised as a network SME within the team

Ability to lead complex technical delivery and problem resolution independently

Strong understanding of:

Secure-by-design networking

Network segmentation strategies (macro and micro segmentation)

High availability, resilience, and fault tolerance

Hands-on experience implementing and operating Cisco ACI environments

Ability to contribute to design decisions in partnership with architecture teams

✅ Behavioural & Professional Skills

Ownership & Accountability: Takes responsibility for network stability, performance, and security

Technical Leadership: Influences engineering standards and solutions without direct line management

Security Focus: Embeds secure-by-design principles into all network solutions

Collaboration: Works effectively across infrastructure, security, and cloud teams

Communication: Clearly articulates technical concepts and designs

Continuous Improvement: Drives optimisation, automation, and simplification initiatives

✅ Preferred Qualifications

Certifications such as:

Cisco (CCNP / CCIE)

F5 certifications

Cloud networking certifications (Azure / GCP)

Exposure to:

Network automation tools (Ansible, Terraform, etc.)

Container networking and modern application delivery

Colt Technology Services

Contact Details:

Colt Technology Services Recruitment Team