Theodoros S. - Network Security Architect

Pyrgetos, Greece

Experience

Apr 2024 - Present

1 year 9 months

Pyrgetos, Greece

Hybrid

Architect network solutions in hybrid and heterogeneous environments, both in cloud and on premises.
Workshop and Proof of Concept.
System and Network hardening.
Penetration Testing and Vulnerability analysis.
Packet Analysis, and identification of root causes in heterogeneous and complex networks.
API securtiy testing.
ISMS Design and Development, Private Sector. Assisted companies of various sizes and complexity by leading projects with the aim to design and develop robust enterprise information security (ISO 27001 compliant).
Produce and maintain technical documentation.
Technologies and Methodologies used: OWASP, MITRE ATT@CK, ITIL v4, COBIT, Cisco IOS XE and NX-OS, Cisco Thousandeyes, Aruba, pfSense, Azure, AWS, Kali Linux, Burpsuite, Maltego, Metasploit, Nessus, Wireshark/tcpdump, Grafana, Zabbix, Proxmox, Debian

Jan 2018 - Apr 2024

6 years 4 months

Munich, Germany

Hybrid

Team Leader of IT & Network and responsible for the overall company's security posture
Architect network solutions in hybrid and heterogeneous environments, both in cloud and on premises.
Management of IT & Network and responsible for the overall company's security posture.
Produce and maintain technical documentation and guides leveraging Jira Confluence.
System Engineering Linux Clusters and Data Center farms.
Troubleshooting networks and applications performance.
System hardening following industry's best practices.
Vulnerabilities Assessments.
Technologies and Methodologies used: ITILv4, COBIT, SD-WAN Zscaler, Cisco IOS XE and NX-OS, pfSense, Fortinet, Sophos,Aruba Docker/Ansible, Microsoft Azure, AWS Linux, Proxmox, VMWare, F5 Load Balancers, Palo Alto, Shell Scripting Network Automation with Python Paramiko, Wireshark/tcpdump, Nessus

Jan 2017 - Dec 2018

2 years

Munich, Germany

Monitoring & Control of GALILEO ground segment devices.
Performing Troubleshooting Activities.
Performing Contingency Activities.
Trouble Ticket Management.
Testing & Integration.
Review of element/segment operative procedures.
Contribution to preparation of reports.
Technologies and Methodologies used: Linux, SNMP, Sophos, Forcepoint, GDATA, openLDAP, Alcatel-Lucent Switches & Routers

Jan 2015 - Dec 2017

3 years

Thessaloniki, Greece

Analysis of business needs of potential customers.
Workshop and Proof of Concept.
Implementation of IT projects according to the business needs.
Maintenance of the overall company's onprem infrastructure.
Second & Third level support.
Technologies and Methodologies used: CISCO Routers/Switches, Barracuda Load Balancers,Virtualization (VMWare vSphere, Hyper-V), Dell Servers & Storage, VoIP technologies (Cisco Call Manager, CUCM, Asterisk , FusionPBX), Linux

Jan 2008 - Dec 2015

8 years

Athens, Greece

Network design & implementation of the Public Insurance Institution of Greece. This project included Cisco Switches & Routers, Cisco ASA for the perimeter security, Barracuda Load Balancers. More than 100 points of presence, directly connected to the main infrastructure, in the whole country with WAN (BRI and Serial).
Network design & implementation of Mesh Wireless Network in the Port Authority of Piraeus, with Cisco Aironet, Cisco Wireless Controllers and Cisco Switches & Routers.
Design and configuration of site to site VPN with private banks with Cisco ASA.
Network design & implementation of Greek Police network with Fortinet appliances.
Network design & implementation of Ministry of Development with Cisco Routers/Switches and Cisco ASA and IPS for the perimeter security.
Network implementation of the information system in Public Transportations of Athens, with HP MSM Wireless Controllers and HP5800 Layer 3 switches.
Technologies and Methodologies used: Cisco Catalyst Switches 2924, 2950, 3550,3760X Stackwise 3950,Cisco Layer 3 Switches 6500, Cisco Routers, Barracuda Loadbalancer, Barracuda WebFilter, Barracuda Antispam, HP MSM Wireless Controllers, HP Procurve Switches, Fortinet FortiGate, FortiAnalyzer, FortiManager

Jan 2007 - Dec 2008

2 years

Athens, Greece

Member of the internal IT department with focus on networks.
Daily network and systems checks.
Redesign of the local network infrastructure according to the needs of the company.
Presales of network equipment.
Technologies and Methodologies used: Cisco Catalyst Switches 2924, 2950, 3550, Microsoft Servers.