Célestin Matte
DevOps System Administrator
I'm a freelance DevOps system administrator specialized in Linux infrastructure. I deploy and migrate systems using Ansible on GCP and AWS, ensuring automation, traceability and documentation.
I improve system resilience through monitoring, redundancy, and automated redeployment. I also enjoy the challenge of modernizing and documenting legacy infrastructures.
With an engineering degree, a PhD in computer science (network privacy) and over 10 years of experience maintaining Linux infrastructures, I work autonomously and efficiently in international environments. I've been a full-time system administrator for the past 5 years.
- infrastructure automation,
- system monitoring,
- backup and disaster recovery strategies,
- cloud migration,
- service setup (web, email, video conferencing, VPN, etc.),
- infrastructure modernization,
- CI/CD pipeline design and implementation,
- system maintenance,
- SSL/TLS certificate management.
Technical skills:
- DevOps & CI/CD: Ansible, Docker, Git, Gitlab CI/CD, Bash
- Cloud: GCP, AWS, OVH, Gandi
- OS: Linux (Debian, Arch Linux, Ubuntu, CentOS)
- Web servers & databases: Apache, NGINX, PostgreSQL, MariaDB
- Monitoring & virtualization: Nagios, vSphere
- Mail infrastructure: Postfix, Exim, Dovecot, SPF/DKIM/DMARC configuration
- Programming: Python (Django, Flask)
- Infrastructure & orchestration: Kubernetes and Terraform (working knowledge)
Strasbourg (France) & remote
Software in the Public Interest
DevOps Sysadmin
-
Migrate running systems to up-to-date and maintained cloud-based servers or services:
- Migration of systems to Google Cloud Engine and AWS:
- websites
- mailing lists (mailman)
- mail servers (postfix/exim)
- Migration of Git servers to Gitlab.
- Google Workspace configuration.
- DNS zones transfer from Mythic Beasts to Gandi, coordinating with associated projects maintainers.
- Adding monitoring and backup solutions.
- Writing extensive documentation on the whole infrastructure and processes.
- Rewriting a Flask web application in Django.
- Write Ansible script to install open source mailing list software PGLister, work on patches with upstream.
- Configure SPF, DKIM and DMARC.
- Set up deployment testing for CI's pipeline of PGLister and PGArchives.
- Contribution to Debian and PostgreSQL projects: Debian-reimbursements, PGLister, PGArchives, PGWeb
- Key challenges: High autonomy, coordination with of open source projects maintainers
- Technologies: Ansible, Google Cloud Engine, AWS, Gandi, Postfix, Django, Gitlab, Docker, pgBackRest
IRIS (Canon group)
System administrator
-
Manage ~50 Linux servers:
- Upgrade all servers
- Implement security measures
- Debug issues and critical crashes
- Introduce automation with Ansible
- Update documentation
- Communicate with teams
- Key challenges: Autonomy, urgent fixes, security
- Technologies: Debian, Ubuntu, CentOS, Fedora, Ansible, Bash, Apache, OpenVPN, Samba, VMWare vSphere, Jira, Confluence
Demo Wi-Fi tracking system
-
Installation of a Wi-Fi tracking demonstration prototype:
- Development of the Wi-Fi tracking software
- Configuration of a minimal Arch Linux system
- Development of Ansible scripts to handle the different possible deployments scenarios
- Configuration of dhcpd for the network of ~15 machines to deploy and configure automatically
- Minimize risk of system crashes and hardware faults
- Deployments:
- Cité des Sciences et de l'Industrie (11 months)
- CITI laboratory showroom
- CNIL showroom
-
Key challenges:
- Availability of a system running in autonomy for several months
- fully automatic self-deployment and configuration of the network of ~15 machines
- Technologies: Arch Linux, dhcpd, Ansible, Python
Running a video game for a year
-
Adapting and running a video game (Sistexpress) for a year (~50 players):
- Rewriting a web PHP game into a fast-paced version.
- Improving the interface with Ajax.
- Monitoring CPU consumption and profiling code for optimization.
- Configuring automatic backups.
- Community management.
-
Key challenges:
- Availability
- Controlling CPU consumption
- Technologies: Ubuntu, Apache, PHP, PHP-FPM, MariaDB, nmon, Symfony, Ajax
Packaging for Arch Linux
-
Maintaining packages for Arch Linux user repository (AUR):
- Troubleshooting old application for compatibility with modern system.
- Setting up Gitlab CI.
- Communication with maintainers of dependencies and packagers of other distributions.
- Handling user-reported issues.
-
Key challenges:
- Maintaining an application utilizing unfamiliar technologies.
- Communication with various actors.
- Technologies: Arch Linux packaging, Gitlab CI, OCaml
Maintaining personal servers
-
Maintaining 4 personal servers since 2013:
- Various services: email, Web, video-conference, VPN,
- Self-hosting,
- Automating backups and upgrades,
- Monitoring,
- Constant focus on security (chroot, network segmentation...).
-
Key challenges:
- Availability
- Automation
- Technologies: Arch Linux, Debian, Apache, Postfix, Flask, MariaDB, OpenVPN, Jitsi, Docker
Writing articles for general public technical journals
-
Wrote 7 articles on various topics:
- PhD thesis' topics: fingerprinting, MAC address randomization
- Neural networks
- Bash
-
Key challenges:
- Writing for the general public and technicians
PhD + Postdoc
-
- Topics: Privacy, Wi-Fi & Web tracking, Fingerprinting, GDPR.
- 6 publications in peer-reviewed conferences (1 top-ranked) + 1 journal publication.
- Demo Wi-Fi tracking system installed at the Cité des Sciences et de l'Industrie and in CNIL's showroom (see above).
- Crawled 28 000 websites using a custom python/Selenium script.
- Teaching (3 years).
- Team work.
- Collaboration with lawyers.
- Industry impact: work cited by Google, work discussed at an IEEE session, work lead to a complaint by NOYB to the CNIL relayed by the press.
- See my former research résumé for more details.
-
Selected research deliverables:
- Slides of my PhD defense on Wi-Fi tracking. The introduction is written to be understandable by a large public.
- Study on cookie banners. Related research article was published in a top-ranked conference.
- Software:
- Browser extension to verify consent registered by cookie banners.
- Web application for visualization of data related to an industry-standard cookie banners framework (auto-updated).



