0
Windows servers supported
SYSTEMS OPERATIONAL // MANCHESTER, UK
Selected work across digital infrastructure.
I’m Callum, an IT infrastructure and network technician. This portfolio documents infrastructure, networking, identity, endpoint management, cloud, automation and wider technical work I have contributed to.
callum@infra:~$ whoami
IT Infrastructure & Network Technician
callum@infra:~$ cat stack.json
{
"networking": ["VLANs", "VPN", "DNS", "Routing"],
"systems": ["Windows Server", "Linux", "Azure"],
"identity": ["Entra Connect", "Hybrid Join", "Intune"],
"security": ["Sophos", "ZTNA", "MFA", "FIDO2"],
"automation": ["PowerShell", "GitLab CI/CD", "Python"],
"development": ["Web Design", "AI Prompting", "Twilio", "Ascend"]
}
portfolio_mode: experience evidence // employer view
HYBRID
AD, Entra ID and Intune
LINUX
Internal application hosting
UK
Manchester-based
01 // Selected technical work
Infrastructure projects and responsibilities.
Examples of work completed or supported across business environments, technical projects and lab-based development.
PROJECT_001● COMPLETED
Active Directory domain controller modernisation
My work: promoted Windows Server 2022 domain controllers, verified DNS, replication and SYSVOL health, transferred FSMO roles, investigated DFSR issues and documented the controlled removal of the legacy controllers.
PROJECT_002● IN USE
Hybrid identity and Intune-managed endpoints
My work: supported a hybrid environment using on-premises Active Directory, Entra Connect and Entra ID, with Windows devices hybrid joined and managed through Intune configuration, compliance and application policies.
PROJECT_003● LIVE
Self-hosted GitLab CI/CD platform
My work: deployed and administered a self-hosted GitLab instance, configured repositories, SSH access and a shell runner, then created a test pipeline for controlled deployment to an internal Linux server.
PROJECT_004● OPERATING
Internal application hosting layer
My work: supported multiple internal Flask applications behind NGINX, using Gunicorn and systemd services, TLS termination, path-based routing, authentication forwarding and extended proxy timeouts.
PROJECT_005● DOCUMENTED
Acquisition network discovery and integration planning
My work: produced structured discovery documents covering IP ranges, VLANs, routing, IPsec tunnels, SSL VPN access, firewall and switching ownership, hardware, accounts and third-party dependencies.
PROJECT_006● IMPLEMENTED
Sophos ZTNA implementation
My work: planned, configured and implemented Sophos ZTNA from scratch, integrating the platform into the existing network and identity environment. This included defining application resources and access policies, validating secure remote access and troubleshooting connectivity and session behaviour.
PROJECT_007● CONCEPT
Operational monitoring concepts
My work: scoped an internal dashboard for Windows logon activity, server health and operational status across the environment, including the events and data needed for central visibility.
PROJECT_008● SCOPED
FIDO2 security key authentication
My work: investigated a security-key-only authentication model for users unable to use mobile phones, including Entra authentication-method policies, enrolment requirements and account recovery considerations.
02 // Technical stack
Tools, protocols and platforms.
Platforms and technologies I have administered, supported, configured or used in project work.
Networking
TCP/IP, VLANs, routing, DNS, DHCP, IPsec, SSL VPN, NAT and infrastructure discovery.
Systems
Windows Server, Active Directory, Group Policy, DFSR, Linux, NGINX and systemd.
Security
Sophos Firewall, Sophos Central, ZTNA, MFA, FIDO2 and access segmentation.
Identity & endpoints
Entra ID, Entra Connect, hybrid join, Intune enrolment, compliance policies, configuration profiles and managed Windows devices.
Automation
PowerShell, Python, Git, GitLab runners, YAML pipelines and repeatable deployment workflows.
Applications
Flask, Gunicorn, Tomcat, reverse proxies, TLS and internal service publishing.
Operations
Monitoring, incident diagnosis, change planning, documentation and platform ownership.
Current focus
Infrastructure engineering, network design, secure automation and observable systems.
03 // Personal development
Skills developed beyond core infrastructure.
Areas I have actively developed through hands-on projects, experimentation and operational work.
Website design and front-end development
Developing modern, responsive websites using HTML, CSS and JavaScript, with a focus on clear information architecture, interactive interfaces, accessibility and deployment to live domains and hosting platforms.
HTMLCSSJAVASCRIPTRESPONSIVE DESIGNWEB HOSTING
AI prompting and technical workflows
Building structured prompts for technical troubleshooting, documentation, planning and content development. I focus on supplying context, constraints and validation steps so AI output is useful, accurate and repeatable.
PROMPT DESIGNTECHNICAL RESEARCHDOCUMENTATIONWORKFLOW DESIGN
Cloud telephony and phone-system setup
Developing experience with business phone platforms including Twilio and Ascend, covering user and handset setup, number provisioning, call routing, queues, testing and troubleshooting day-to-day telephony issues.
TWILIOASCENDCALL ROUTINGNUMBER PROVISIONINGUSER SETUP
04 // Professional profile
How my experience has developed.
I started in 1st Line IT support, building a strong foundation in user support, device setup, account administration, Microsoft 365 and day-to-day troubleshooting.
As I progressed into 2nd Line support, my responsibilities expanded to include access to VMware vCenter and ESXi, provisioning and managing Windows servers, Active Directory, Group Policy, firewall administration, VPNs, endpoint management and more complex technical incidents.
Through that work I developed a particular interest in networking and infrastructure. I now contribute to projects involving network discovery, VLANs and routing, Sophos firewalls and ZTNA, hybrid identity, Intune, server modernisation, Linux application hosting and GitLab CI/CD.
My current direction is toward an Infrastructure Engineer role with greater ownership of technical design, implementation, automation, documentation and the ongoing operation of business-critical platforms.
05 // Evolution log
Progression of technical responsibilities.
1ST LINE
User support and technical foundations
Handled service desk tickets, device preparation, user and account administration, Microsoft 365 support, hardware troubleshooting and clear communication with end users.
2ND LINE
Systems administration and escalated support
Took on more complex incidents and gained responsibility for VMware vCenter and ESXi, Windows server provisioning and management, Active Directory, Group Policy and endpoint administration.
INFRASTRUCTURE
Networking, security and platform projects
Expanded into Sophos firewall and VPN management, VLANs and routing, ZTNA, hybrid Entra identity, Intune, server modernisation, Azure, Linux hosting and GitLab CI/CD.
CURRENT DIRECTION
Infrastructure Engineer
Progressing toward broader ownership of infrastructure design, implementation, automation, security, documentation, monitoring and long-term platform reliability.
06 // Contact
Employment and professional enquiries.
For roles relating to IT infrastructure, networking, systems administration, security or endpoint management.