IT Systems & Network Engineer · Athens, Greece

15+ years keeping enterprise IT
infrastructure
running.

I'm Konstantinos Sigalas — an IT Systems & Network Engineer supporting large organizations across Microsoft 365, Windows Server, Cisco networking, virtualization and unified communications. Currently responsible for the full IT environment of ~500 users at the Viohalco Group.

15+
Years in IT
~500
Users supported
CCNA
Certified
MSc
Networks
About

A reliable engineer behind the scenes.

I specialize in the infrastructure, systems and networks that large organizations depend on every day. Over 15+ years I've moved from structured cabling and unified communications into full enterprise systems engineering — administering Microsoft 365, Windows Server, VMware and Cisco networks, and supporting hundreds of users end to end.

Today I own the IT environment for ~500 users across 7 buildings at the Viohalco Group in Marousi, keeping servers, networking and telephony running with >99% uptime. My background combines a Cisco CCNA, an MSc in Digital Communications & Networks and hands-on experience across the full IT stack.

I work methodically — confirm the symptoms, isolate the cause, apply the fix, and document it so it never happens again. When I'm off the clock, you'll find me exploring lesser-known corners of Greece with a drone and a camera.

Quick facts

RoleIT Systems & Network Engineer
LocationAthens, Greece
Experience15+ years
CloudMicrosoft 365 · Azure
VirtualizationVMware vSphere
LanguagesGreek · English
Skills

What I work with.

A full stack of infrastructure, cloud, networking and unified-communications expertise — built to keep environments secure, available and easy to manage.

☁️

Microsoft 365 & Azure

M365 Administration, Azure Fundamentals, Exchange Online, licensing and cloud identity.

🖥️

Windows Server & OS

Windows Server 2016/2022, Windows 10/11, Linux and macOS in mixed enterprise environments.

🌐

Cisco Networking

Routers & switches, VoIP, WiFi, structured cabling and fiber optics (CCNA certified).

🧩

Virtualization

VMware vSphere — install, configure and manage virtual infrastructure.

🗄️

Databases & Backup

MS SQL 2017–2022 administration, Symantec Backup Exec and data-protection practices.

📞

Unified Communications

IP telephony, Asterisk, call-center platforms and MPS (uniFLOW, YSOFT).

Experience

Career highlights.

Jan 2020 – Present

IT Systems Engineer

Viohalco Group of Companies — Marousi, Athens
  • Provide IT support for ~500 users across 7 buildings on the Marousi campus (laptops, MFPs, telephony, mobiles).
  • Maintain networks, servers and data-centre racks, sustaining >99% uptime of core business systems.
  • Resolve ~40–60 tickets/week across hardware, connectivity, Microsoft 365 and user accounts.
  • Support Windows Server, VMware virtualization and backup operations for business continuity.
May 2018 – Dec 2019

Unified Communications Engineer / Consultant

COMSYS S.A. — Kifisia, Athens
  • Designed, installed and parametrized UC and outbound-dialing platforms for ~54 contact/call centers serving 5,000+ agents.
  • Provided technical consulting and post-installation support to enterprise clients.
May 2016 – May 2018

Software Consultant & Product Specialist

CPI S.A. — Tavros, Athens
  • Monitored a fleet of ~5,500 MFPs via remote diagnostics for proactive maintenance and full device control.
  • Deployed and supported YSOFT print management (MPS) and QNAP, Kodak scanners and interactive whiteboards.
2007 – 2016

Earlier roles — Networks, VoIP & IT Support

INTERSYS · 3NET Communications · DATABANK · O.T.E.
  • INTERSYS: uniFLOW MPS support across ~80 customers; monitored ~10,000 Canon MFPs via remote diagnostics.
  • 3NET: installed VoIP at Panteion University and programmed Asterisk telephone exchanges.
  • DATABANK & O.T.E.: backup administration, network maintenance and structured cabling (Cat 5e / fiber).
Credentials

Certifications & Education.

🛜

Cisco CCNA

Routing & Switching (2014)

☁️

Microsoft Azure Fundamentals

+ M365 Administrator · Managing Modern Desktop

🧩

VMware vSphere

Install, Configure, Manage [V7]

🗄️

MS SQL 2017

Administering a SQL Database Infrastructure

🎓

MSc Digital Communications & Networks

University of Piraeus (2013)

📡

BSc Teleinformatics & Management

TEI of Epirus (2008)

Let's build something reliable.

Have a role, a project, or an infrastructure challenge in mind? I'd love to hear about it.