09/22/2025 updated
100 % available
Administrator of Linux and Cloud systems
Mainz, Germany
Germany +1
MSc Civil Engineeringinfo: Germany, Greece
Lisp (Programming Language)AutomationAWK (Programming Language)Bash ShellCloud ComputingLinuxDomain Name System (DNS)ElasticsearchFortran (Programming Language)Vim (Text Editor)HAProxyPython (Programming Language)PostgreSQLUnix ShellNginxNmapAnsiblePrometheusTcpdumpWiresharkSed (Programming Language)Cloud Platform SystemGrafanaGitlab-ciKubernetesIptablesKibanaDocker
- Linux: shell (bash), sed, awk, vim, nginx, docker, systemd
- Networking: Iptables, DNS, wireguard, socat, ncat, nmap, tcpdump, wireshark, IPVS, HAProxy
- Orchestration, Automation: Kubernetes, Ansible, Cloud-init, Gitlab CI/CD
- Observability: Prometheus, Grafana, AlertManager, Fluentbit, ElasticSearch, Kibana
- Development: Python, Javascript, PostgreSQL, AWK, Common Lisp, Racket, Fortran
Languages
DeutschBasic knowledgeEnglischFluentGriechischNative speakerItalienischBasic knowledge
Project history
- Operation and joint development (web scraping and database) of a web application https://sm.tst.gitsis.eu to search and compare prices in large chains of greek supermarkets. Technologies: Python, SQLite, Gitlab CI/CD, Linux, Hetzner Cloud, AWS S3, HTTP REST APIs
- Administrator of cloud infrastructure, using the Linux operating system on QEMU VMs and Hetzner Cloud VMs. Technologies: cloud-init, bash, systemd, DNS, Ansible …
- Administrator of networks, including subnetting, packet-filtering/firewalls (e.g. Linux IPTables), automating installation of VPNs (Wireguard), operating DNS servers (unbound, dnsmasq). Familiar with relay tools (socat), network scanners (nmap), packet analyzers (tcpdump and wireshark), layer 4 load balancers (IPVS, HAProxy, nginx).
- Administrator of public key infrastructure, using an external Certificate Authority (Letsencrypt) to secure public facing websites, as well as managing own Certificate Authority for Zero Trust internal networks, e.g. for HTTPS, for TLS dataflows or for setting up SSH Certificates to avoid the Trust On First Use (TOFU) problem.
- Administrator of software for internal usage for purposes of: real time chatting (Mattermost + dependencies), company email (Mailcow + dependencies), several HTTP servers and load balancers (nginx), user authentication and authorization (LDAP, Authelia), monitoring (Prometheus, Grokexporter, Grafana, AlertManager), logshipping (Fluentbit, incl. extraction of structured information from logs), central logging (ElasticSearch, incl. configuration, sizing, backups, automated updates and visualizations in Kibana)
- Administrator of Kubernetes Clusters and Container runtimes on which workloads of point 5 are deployed, incl. automated setup/teardown of Clusters and experimenting with various CRI, CNI, CSI Interfaces. Technologies: Kubernetes, helm, kustomize, docker, docker-compose, containerd, cri-o, Linux, Ansible
- I take pleasure in assisting less experienced colleagues, often working in pairs with them on their tasks