Konstantinos is available for hire
Hire KonstantinosKonstantinos Tzikakos
Verified Expert in Engineering
System Administrator and Developer
Athens, Greece
Toptal member since December 19, 2022
Bio
Konstantinos is a senior Linux system administrator with extensive experience in virtualization and web hosting environments, customer and technical support, and troubleshooting. He is proficient with cPanel, holds the WHM system administrator certification, and is passionate about technical documentation. Konstantinos is also experienced with ISO 27001 and GDPR best practices.
Portfolio
Hellenic Academic & Research Institutions Certification Authority (HARICA)
Apache, NGINX, MySQL, Bash, Ubuntu Server, SSL Certificates, Virtualization...
Self-employed
NewTek NDI, MikroTik, Resolume, Projection Mapping, 3D Video...
IpHost.net
Linux, Apache, MySQL, CentOS, Rundeck, cPanel, Plesk, Virtualmin, Let's Encrypt...
Experience
- Troubleshooting - 10 years
- Monitoring - 9 years
- Web Hosting - 8 years
- cPanel - 8 years
- Technical Documentation - 8 years
- Linux - 7 years
- DNS - 7 years
- SSL Certificates - 5 years
Availability
Part-time
Preferred Environment
cPanel, DNS, Let's Encrypt, SSL Certificates, Technical Documentation, Web Hosting, Troubleshooting, Linux, Monitoring, PKI
The most amazing...
...thing I've created is some custom Apache-MySQL-PHP-FPM configurations in order to optimize hundreds of underperforming VMs, keeping their key customers happy.
Work Experience
Linux System Administrator L2
2022 - PRESENT
Hellenic Academic & Research Institutions Certification Authority (HARICA)
- Upgraded Ubuntu Server virtual machines to the latest long-term support (LTS) and migrated all services with zero downtime.
- Gained advanced knowledge of certificate authorities, CA/Browser Forum, digital certificates, and secure products.
- Updated any outdated documentation in the organization's wiki. Joined a network operations center (NOC) team.
Technologies: Apache, NGINX, MySQL, Bash, Ubuntu Server, SSL Certificates, Virtualization, VMware, SSL, NetBox, Jira, CentOS, Systems Monitoring, Nagios, Netdata, PKI, Digital Certificates, Digital Signatures, X.509 Certificates, Certbot, Keepalived, Corosync, Technical Support, Dovecot, Postfix, Troubleshooting, Technical Documentation, Linux, Cloudflare, DNS, Web Hosting, Let's Encrypt, Plesk, Agile, DDoS, GDPR, Ethical Hacking, Cybersecurity, Web Security, IT Security, Monitoring, Mailchimp, Markdown, Wiki.js, Atlassian, Confluence, Shell, Bash Script, WordPress, Software Troubleshooting, Proofreading, Website Migration, Optimization, Penetration Testing, SpamAssassin, APIs, GitLab CI/CD, GitLab, Git, W3 Total Cache, Memcached, Redis Cache, Online Certificate Status Protocol (OCSP), Search Engine Optimization (SEO), CloudLinux, Ansible, Cloud-Init, Security, Risk Management, Test Documentation, Documentation, Technical Writing, Testing, Quality Assurance (QA), Antivirus Software, Database Security, IDS/IPS, Writing & Editing, TCP/IP
Video Projection Mapper
2010 - PRESENT
Self-employed
- Worked actively with 3D projection mapping for indoor and outdoor installations, concerts, corporate events, and parties.
- Acted as a technician specialized in NDI and video over IP setups using MikroTik router boards and switches.
- Used Resolume Arena software and analog and mixed media projections.
Technologies: NewTek NDI, MikroTik, Resolume, Projection Mapping, 3D Video, Open Broadcaster Studio (OBS), Networking, Graphic Design, Technical Support, Troubleshooting, Hardware Troubleshooting, Technical Documentation, Photoshop CS6, Illustrator CS6, Access Points, RouterOS, Software Troubleshooting, Testing & Maintenance, Web Security, Cybersecurity, IT Security, Email Templates, Newsletter Templates, Microsoft Power BI, W3 Total Cache, Search Engine Optimization (SEO), Security, Risk Management, Test Documentation, Documentation, Technical Writing, Testing, Quality Assurance (QA), Writing & Editing, TCP/IP
Linux System Administrator L1 and L2
2020 - 2022
IpHost.net
- Joined the company as a member of L1 technical support and was promoted to the L2 system administrator in less than a year.
- Built a whole knowledge base from scratch to meet an end customer's needs, reducing incoming support tickets by 30%. Created technical documentation and guides for common tasks and procedures.
- Created a custom Apache-MySQL-PHP-FPM configuration for e-shops, saving over 400 virtual machines suffering from poor performance due to misconfiguration.
Technologies: Linux, Apache, MySQL, CentOS, Rundeck, cPanel, Plesk, Virtualmin, Let's Encrypt, Technical Documentation, DNS, Systems Monitoring, Zabbix, Kayako, SSL Certificates, Exim4, Postfix, Dovecot, DDoS, NetBox, RackTables, Proxmox, Inventory Management, Technical Support, Helpdesk, Keepalived, Certbot, X.509 Certificates, Digital Certificates, SSL, Jira, Troubleshooting, Hardware Troubleshooting, Bash, Cloudflare, Web Host Manager (WHM), Web Hosting, NGINX, Agile, Windows PowerShell, Customer Support, GDPR, Ethical Hacking, Cybersecurity, Web Security, IT Security, Monitoring, Mailchimp, Markdown, Wiki.js, Atlassian, Confluence, Shell, Bash Script, WordPress, Software Troubleshooting, Virtualization, Proofreading, Website Migration, Optimization, Penetration Testing, Windows Server, SpamAssassin, Email Templates, Newsletter Templates, Microsoft Power BI, APIs, GitLab CI/CD, GitLab, Git, W3 Total Cache, Memcached, Redis Cache, Search Engine Optimization (SEO), CloudLinux, Ansible, Security, Risk Management, Test Documentation, Documentation, Technical Writing, Testing, Quality Assurance (QA), Antivirus Software, Database Security, IDS/IPS, Writing & Editing, TCP/IP
L1 and L2 Technical Support Team Lead
2018 - 2020
Wind Hellas Telecommunications
- Transitioned from L1 technical support to team lead for corporate technical support within the first year.
- Handled VIP and high-value customers' cases and provided customer care.
- Trained new L1 and L2 team members on our tools, procedures, and GDPR.
- Created detailed documentation for the technical team's procedures.
Technologies: VoIP, Networking, Access Points, RouterOS, MikroTik, Cisco Meraki, PBX, Troubleshooting, Customer Support, Key Performance Indicators (KPIs), DNS, FTTH, ADSL, Inventory Management, Technical Support, Helpdesk, Jira, Technical Documentation, Systems Monitoring, Cloudflare, Web Hosting, Windows PowerShell, ICT Training, GDPR, Cybersecurity, Web Security, IT Security, Monitoring, Mailchimp, Markdown, Wiki.js, Atlassian, Confluence, Shell, Bash Script, WordPress, Software Troubleshooting, Cabling, Proofreading, Website Migration, Optimization, SpamAssassin, Email Templates, Newsletter Templates, APIs, Git, W3 Total Cache, Memcached, Redis Cache, Search Engine Optimization (SEO), Security, Risk Management, Test Documentation, Documentation, Technical Writing, Testing, Quality Assurance (QA), Antivirus Software, Writing & Editing, TCP/IP
ICT Officer
2015 - 2017
Samaritan's Purse
- Managed all remote offices via Cisco Meraki managed routers and MikroTik switches and router boards and all devices via Cisco Meraki MDM.
- Supported 300+ staff members in seven different locations in Greece.
- Managed a 1,000+ inventory of the organization's ICT assets.
- Trained staff on the organization's ICT procedures.
Technologies: Cisco Meraki, MikroTik, RouterOS, Access Points, Cabling, VSAT, Hardware Troubleshooting, Software Troubleshooting, Testing & Maintenance, Inventory Management, Helpdesk, Technical Support, Networking, Procurement, ICT Training, GDPR, WordPress, Troubleshooting, Technical Documentation, Windows PowerShell, Customer Support, Cybersecurity, Web Security, IT Security, Mailchimp, Markdown, Monitoring, Proofreading, Website Migration, Optimization, Email Templates, Newsletter Templates, W3 Total Cache, Search Engine Optimization (SEO), Security, Risk Management, Test Documentation, Documentation, Technical Writing, Testing, Quality Assurance (QA), Antivirus Software, Writing & Editing, TCP/IP
Experience
Standalone Knowledge Base for a Web Hosting Company Embedded in Its Ticketing Platform
The web hosting company received a comprehensive knowledge base with guides, tutorials, and detailed articles on all common issues reported via support tickets. The knowledge base is available to all registered company customers once they log into their accounts, as some articles and guides include company-specific information. In the technical support section of their account, the end user or customer searches for a relevant article in the knowledge base before submitting an actual support ticket.
This project was entirely based on my input and technical writing. As a system administrator, I already had a clear overview of all incoming support tickets. The software used for the knowledge base is Atlassian's Confluence, combined with the existing Kayako ticketing platform, which enables the rest of the support team to use these items as ready-made macro responses to incoming support tickets.
This solution reduced incoming support requests by over 30% within the first six months of its launch and saved time for the team. If a customer sent a ticket covered by the knowledge base, the team replied with three clicks instead of writing a new guide from scratch.
This project was entirely based on my input and technical writing. As a system administrator, I already had a clear overview of all incoming support tickets. The software used for the knowledge base is Atlassian's Confluence, combined with the existing Kayako ticketing platform, which enables the rest of the support team to use these items as ready-made macro responses to incoming support tickets.
This solution reduced incoming support requests by over 30% within the first six months of its launch and saved time for the team. If a customer sent a ticket covered by the knowledge base, the team replied with three clicks instead of writing a new guide from scratch.
DPO and Abuse Reports PoC
I provided two years of hands-on data protection as a DPO in a major web hosting provider. I oversaw the organization's compliance with data protection laws and regulations, such as the European Union's General Data Protection Regulation (GDPR), as well as the main point of contact for any incoming abuse reports about the organization's infrastructure, like copyright infringement reports, cyber-attacks, etc.
Some of the key responsibilities of a DPO:
► Advising the organization on data protection compliance matters
► Conducting data protection impact assessments (DPIAs)
► Responding to data subject rights requests
► Providing training on data protection to employees
► Coordinating with supervisory authorities on data protection issues
► Maintaining records of processing activities
► Acting as a point of contact for data protection authorities and data subjects
► Creating all the respective documentation and procedures
► Training staff members and helping with yearly audits as well as internal auditing
► Monitoring the organization's compliance with data protection laws and regulations
Some of the key responsibilities of a DPO:
► Advising the organization on data protection compliance matters
► Conducting data protection impact assessments (DPIAs)
► Responding to data subject rights requests
► Providing training on data protection to employees
► Coordinating with supervisory authorities on data protection issues
► Maintaining records of processing activities
► Acting as a point of contact for data protection authorities and data subjects
► Creating all the respective documentation and procedures
► Training staff members and helping with yearly audits as well as internal auditing
► Monitoring the organization's compliance with data protection laws and regulations
Bash Script to Change the Character Set in a MySQL Database
A simple yet effective Shell script was used to change and convert the MySQL database's character set. It also collated and checked the database after changes. This script was created as a go-to solution in cases of new or imported MySQL databases with charsets that were not supported, resulting in wrong characters in the end product that used a specific database. The script can be used in any Linux environment as is, just by changing the database credentials.
Education
2007 - 2010
Bachelor's Degree in Multimedia and Internet Technology
University of Salford - Manchester, UK
Certifications
FEBRUARY 2022 - PRESENT
cPanel & WHM System Administrator I Certification (CWSA-1)
cPanel
Skills
Libraries/APIs
Cloud-Init
Tools
Kayako, Apache, Let's Encrypt, Virtualmin, Cisco Meraki, Photoshop CS6, Illustrator CS6, Exim4, Postfix, Certbot, Keepalived, Open Broadcaster Studio (OBS), SpamAssassin, NGINX, Plesk, Jira, Rundeck, Zabbix, VMware, Nagios, Corosync, Shell, Confluence, Atlassian, Mailchimp, Microsoft Power BI, Git, GitLab, GitLab CI/CD, Ansible
Platforms
cPanel, Linux, CentOS, WordPress, Proxmox, RouterOS, Windows Server
Paradigms
Testing & Maintenance, Search Engine Optimization (SEO), Testing, Agile, DDoS, Penetration Testing
Industry Expertise
Cybersecurity
Storage
Database Security, MySQL, MariaDB, Redis Cache, Memcached
Languages
Bash, Bash Script, Markdown
Frameworks
Windows PowerShell
Other
Web Host Manager (WHM), DNS, Web Hosting, Technical Documentation, Troubleshooting, VoIP, ADSL, Helpdesk, Technical Support, GDPR, Resolume, Projection Mapping, Graphic Design, W3 Total Cache, Test Documentation, Documentation, Technical Writing, Knowledge Bases, Tutorials, Writing & Editing, System Administration, SSL Certificates, Ubuntu Server, Hardware Troubleshooting, SSL, Networking, Access Points, MikroTik, FTTH, Cabling, VSAT, Software Troubleshooting, Inventory Management, ICT Training, NewTek NDI, 3D Video, Monitoring, IT Security, Web Security, Proofreading, Website Migration, Security, Risk Management, Quality Assurance (QA), ISO 27001, Security Policies & Procedures, Policies & Procedures Compliance, Architecture, Business Strategy, SMTP, Spam Filtering, Antivirus Software, IDS/IPS, TCP/IP, Systems Monitoring, Dovecot, Virtualization, NetBox, RackTables, Netdata, PKI, Digital Certificates, Digital Signatures, X.509 Certificates, PBX, Customer Support, Key Performance Indicators (KPIs), Procurement, Cloudflare, Wiki.js, Ethical Hacking, Optimization, Email Templates, Newsletter Templates, APIs, Online Certificate Status Protocol (OCSP), CloudLinux, ISO 9001, Training
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