Technical Lead Architect  ·  Glasgow, Scotland

StevenJohnston

Network and security design for critical national infrastructure and operational technology (OT).

Working across oil and gas, gas and electricity networks, education and the public sector.

What I cover

I'm a technical lead from a network and security background. Much of my work is for critical national infrastructure and OT: oil and gas, gas transmission and electricity distribution. I design and deliver infrastructure for these and other private and public sector clients, and lead a team of consultants.

I have designed and implemented OT networks in oil and gas, gas transmission and manufacturing. On OT work the priority is keeping industrial systems running and kept apart from corporate IT, so new networks are built alongside the old and proven before cutover.

I try to keep designs simple and easy for the client to support once the project is done, and to automate the repetitive parts.

OT & critical infrastructure

  • OT network deployments
  • IT/OT separation
  • Segregated OT environments
  • Data-exchange gateways
  • Offshore platform connectivity
  • Secure third-party access
  • IoT & CCTV zoning

Networking

  • BGP
  • OSPF
  • EIGRP
  • SD-WAN
  • Campus LAN/WAN
  • Traffic engineering
  • Live cutovers

Security

  • Palo Alto
  • Cisco FTD
  • Fortinet
  • Zero trust
  • SASE
  • Segmentation
  • Rule-base rationalisation

Identity & access

  • Cisco ISE
  • TACACS+
  • RADIUS
  • Entra ID / SAML
  • Duo MFA
  • PKI & certificates
  • 802.1X

Cloud & hybrid

  • Azure networking
  • Virtual WAN
  • ExpressRoute
  • Transit hubs
  • NVA firewalls
  • Terraform
  • Bicep

Datacentre

  • Nexus & vPC
  • StackWise Virtual
  • Nutanix
  • PowerScale
  • Cohesity
  • Cisco UCS
  • Colocation builds

Collaboration

  • Cisco CUCM
  • Webex Calling
  • Teams Direct Routing
  • CUBE
  • SIP & SRTP
  • Dial plan design

Automation & AI

  • Agentic workflows
  • LLM APIs
  • MCP
  • Python
  • Infrastructure as code
  • Human-in-the-loop design

Leadership

  • Team of 7
  • Design authority
  • Technical standards
  • Mentoring
  • Programme delivery
  • Stakeholder communication

Career

  • 2024 — present

    Technical Lead

    Sword Group (formerly Ping Network Solutions)

    • Design authority and OT design for an oil and gas merger: a parallel dual-datacentre network onboarding 18 offshore platforms and 3 onshore facilities with zero operational downtime, under a 10-minute well-shutdown limit
    • A segregated OT environment for the same operator, with its own core, firewalls, compute and backup, reachable from corporate IT only through controlled data-exchange gateways
    • Cloud-hosted identity platform for device administration across a national gas network, including its OT design
    • Zero trust network and security architecture in Azure for a critical national infrastructure client
    • Design authority and technical standards across concurrent programmes; manage and mentor 7 consultants

  • 2019 — 2024

    Consultant Engineer

    Ping Network Solutions

    • Secure multi-tenant monitoring and privileged access platform for a critical national infrastructure operator
    • Dual-region Azure monitoring, management and telephony platform for a critical national infrastructure customer, deployed as infrastructure as code
    • Core, perimeter and identity refreshes; cross-vendor firewall migrations; SD-WAN migrations
    • Cloud calling and Microsoft Teams migrations with on-premises coexistence
    • 650-site Cisco Meraki refresh, deployed by an automation platform I built: 60 networks in 10 minutes against an hour each by hand
    • Authored the low-level design and migration runbook on every engagement

  • 2015 — 2019

    Principal Engineer

    Virgin Media Business

    • Technical leadership for large public sector accounts
    • Network and datacentre redesign for a national justice sector organisation
    • Secure video conferencing for a custodial environment, connecting inmates, solicitors, police and courts

  • 2003 — 2015

    Network Engineer, then Senior Network Engineer

    Jabil

    • Led a European-wide LAN, WAN and telephony refresh across 112 manufacturing sites
    • OT network design and implementation for manufacturing production environments
    • Delivered two $3M datacentre builds, in London and Budapest
    • Technical lead for the network integration of an acquired competitor facility in the Netherlands

Tools I have built

Security

Gladius
Checks network devices against security benchmarks and writes up the results.
Vigil
Managed services platform where AI agents help with network, security and ticketing work.

Networking

Parity
Builds a copy of a live network and suggests fixes for an engineer to approve.
Archie
Turns a customer brief into a draft network design and lab topology.
Crucible
Generates switch configs for LAN refreshes and checks them for security.

Engineer tooling

ShellMate
SSH and serial terminal with an AI assistant that suggests commands for you to approve.
CloudForge
Designs and deploys Azure infrastructure from a chat.
Webex Migrate
Moves phone systems from Cisco CUCM to Webex Calling, with a dry run first.

See all of them at tools.clydeford.net

Credentials

SC Cleared UK Government, current CCNP Enterprise through 2027 CCNP Collaboration through 2027 CCNA + 8 Cisco specialisms

Contact

Email me LinkedIn Download CV