About
Rui Guimarães
Over 25 years of Information Technology experience, focused on administering, modernising and evolving business infrastructure.
Get in touchWho I am
Technical experience focused on reliable infrastructure.
I am a Systems Administrator and Infrastructure Engineer with more than 25 years of experience in Information Technology, specialised in Microsoft and Linux systems administration, enterprise infrastructures, networking, virtualisation, cloud, security, monitoring and automation.
I currently work for NOS Empresas, serving through Claranet Portugal, following the integration of Ten Twenty One into Claranet. My role is focused on Microsoft and Cloud systems analysis and administration, with responsibility for the operation, support, modernisation and evolution of enterprise infrastructures.
My professional background spans enterprise and SME environments, including critical operations, managed services, data centres, telecommunications, consulting and technology transformation projects. This experience allows me to analyse technical problems with context, understand real dependencies and propose practical, documented and sustainable solutions.
In this context, I have worked across areas such as Cloud Center of Excellence, NOS Empresas, Managed Services, Microsoft and Cloud, helping ensure operational stability, service continuity, security, technical documentation and continuous improvement of supported platforms.
ruiguimaraes.net is my personal professional presence and a space for technical documentation and knowledge sharing about systems, infrastructure, cloud, security, automation and homelab work.
Earlier in my career, at Hidurbe Serviços within the Plainwater Group, I worked on systems administration and infrastructure involving VMware, Hyper-V, Fortigate, pfSense, data centres and SCADA environments. My background also includes mobile telecommunications and UMTS/GSM network optimisation at Motorola Mobility, as well as experience with ZTE, EDS Portugal and Corpo Técnico.
I believe infrastructure should be simple to administer, secure, resilient, observable and prepared to grow with the organisation’s needs. Technology should solve concrete problems, reduce operational risk and make everyday work easier for the teams that depend on it.
Areas of Specialisation
Technical capabilities for enterprise and SME environments.
Administration, integration, troubleshooting and evolution of critical platforms across Microsoft, Linux, cloud and Open Source environments.
Windows Server
Administration of Microsoft environments, Active Directory, DNS, DHCP, Group Policy, File Services, Hyper-V and business-critical services.
Linux
Implementation, administration and troubleshooting of Linux servers, web services, permissions, security, automation and enterprise integration.
Microsoft 365 and Azure
Administration of Microsoft 365, Azure, Entra ID, Exchange Online, hybrid identity, migrations and cloud services designed for operations.
Virtualisation
Experience with VMware, Hyper-V, Proxmox VE, high availability, storage, consolidation and platform modernisation.
Networking and Firewalls
Administration and analysis of business networks, segmentation, network services, Fortigate, pfSense and connectivity between environments.
Automation
Operations automation with PowerShell, Bash, administration scripts, APIs, Git and repeatable, documented processes.
Security
Hardening, access control, configuration review, MFA, policies, logging, backup, recovery and operational risk reduction.
Monitoring
Monitoring, observability, alerts, metrics, dashboards and performance analysis with tools such as Zabbix, Grafana, Prometheus and Wazuh.
Consulting
Technical assessment, requirements gathering, dependency analysis, recommendations, migration planning and decision support.
Project Management
Planning, execution, validation and documentation of technical work in environments that require continuity and predictability.
Technologies
Platforms and tools used in real environments.
Working Philosophy
Practical engineering, documentation and continuous improvement.
Documentation
Configurations, technical decisions, procedures and dependencies should be recorded to support operations, continuity and future work.
Best practices
Every solution should respect the organisation's context, operational requirements and practices that reduce complexity and risk.
Automation
Repetitive tasks should be automated whenever this improves consistency, traceability and operational efficiency.
Security
Security should be part of the solution design, including access, identity, exposure, updates, backup and recovery.
Simplicity
Good infrastructure should be understandable, manageable and maintainable by technical teams without unnecessary dependencies.
Reliability
Monitoring, validation and continuous improvement are essential to keep services available, predictable and aligned with the business.
Continuous learning
Ongoing knowledge development is part of daily work, following the evolution of cloud, security, automation and enterprise platforms.
Currently
Focused on cloud, infrastructure and technology transformation.
I currently work daily with cloud, Microsoft infrastructure, virtualisation, business services, automation, monitoring, security and technology transformation projects. The goal is to help organisations modernise systems, improve reliability, reduce risk and build clear, secure and sustainable infrastructures.
Contact
Shall we discuss your next project?
If you want to modernise your infrastructure, implement new solutions or optimise existing systems, get in touch.