Lionel Rousseau — Senior Linux Systems Administrator & SecOps Analyst

25+ years Linux in production • Security Operations (Blue Team) • SIEM, monitoring, incident response • Business continuity and disaster recovery
CompTIA Security+ (SY0-701) and CySA+ certified • Pays de la Loire, France (Le Mans / Tours)

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Hello, I am
Lionel Rousseau

Linux Systems Administrator & Security Operations
SecOps • Networks • Operations • Incidents

About

  • Email: lionel@rousseau.kr • Phone: +33 685 891 186
  • Location: Pays de la Loire, France
  • Interests: IT, Linux, Aviation, Hiking & Alpine Skiing
  • Availability: Immediate - Open to national mobility
Download CV in PDF format (fr)   Technical Portfolio 2026 (fr)

Professional Objective

Join an infrastructure, operations or security operations team to contribute to Linux systems administration, monitoring of exposed services, service continuity, alert qualification and technical incident remediation.

Professional Profile

Linux-oriented operational profile, I manage, secure, and maintain production infrastructure. My experience includes Linux systems, networking, exposed services, monitoring, logging, backups, disaster recovery planning, and technical incident resolution. As a CompTIA CySA+ certified professional, I am looking to join a team to contribute in the areas of SecOps, security operations, or Linux system administration.

Skills

Key Skills

➔ Linux systems administration, networks & operations

  • Administration, security hardening and operational maintenance of production Linux systems.
  • Deployment and operation of infrastructure services: Web, Mail, DNS, databases, firewalls, virtualization and monitoring.
  • Administration of local networks and hosting infrastructure: firewall, VPN, switching, Wi-Fi, servers, VMs and containerized applications.
  • Monitoring, backups/DR, service continuity and automation of operations tasks.

➔ Security operations & technical investigation

  • Attack surface reduction, access management, hardening and environment segmentation.
  • Analysis of system and network logs, security monitoring / SIEM, alert qualification and remediation.
  • Reliability improvement of exposed services, incident handling and continuous improvement of operations and security practices.
  • CompTIA Security+ and CompTIA CySA+ certified; CSAP stackable certification, Security Analytics Professional.

➔ Technical leadership & coordination

  • Management of cross-functional technical projects: planning, prioritization, quality, deadlines and coordination of multidisciplinary teams.
  • Meeting facilitation, production follow-ups, workload monitoring, reporting, KPIs and activity dashboards.
  • Ability to translate business needs into operational solutions: internal tools, procedures, automation and continuous improvement.

➔ International communication & professional English

  • Fluent English, IT technical terminology and daily exchanges with international partners and clients.
  • Commercial and operational export experience: Europe, USA, South Korea, Japan, negotiation and trade show representation.

Technical Portfolio

My GitHub repositories document work derived from Linux infrastructure operated under real-world conditions: SecOps architecture, monitoring, exposed services, backups/DR, automation, hardening and service continuity.

➔ SecOps Architecture & Linux Continuity
Documentation of a multi-site production infrastructure: segmentation, exposed Web/Mail services, security monitoring, backups, BCP/DR and defense in depth.

➔ Linux Production Backup Toolbox
Scripts and procedures for orchestrating multi-host backups: rsync, LUKS, SHA-256 verification, locking, idempotence and detection of silent failures.

Additional repositories are currently being developed. More to come...

Specialties

My technical foundation has been built over time around Linux administration, exposed services, networking, monitoring and service continuity. I now combine this foundation with a security operations approach reinforced by CompTIA Security+ and CySA+ certifications, with a constant priority: operating reliable, documented and controlled environments.

Linux systems administration

Production, MCO, services

Networks & exposed services

Firewalls, VPN, Web, Mail, DNS

Security operations / SIEM

Logs, alerts, remediation

Automation, backups & DR

Bash, Ansible, continuity

Information Technology

With a father working at IBM Computer Systems, I was exposed very early to computers, systems and technical culture. From the Apple II to the first Red Hat Linux distributions, then to networking and the Internet, this initial curiosity gradually turned into operational practice: server administration, web hosting, mail, DNS, monitoring, backups and security of exposed services.

 
· Systems, networks & security operations

For more than 20 years, I have administered dedicated Linux servers and exposed services for personal and then professional use: Web, Mail, DNS, databases, monitoring, backups and DR. My experience also covers local networking, firewalls, VPNs, virtualization, hardening, log analysis and technical incident remediation. Now certified CompTIA Security+ and CompTIA CySA+, I position this foundation in support of operations, security operations and the reliability of production environments.

  • Linux administration
    Ubuntu, Debian, CentOS, Kali...
  • Virtualization & containers
    Proxmox, VMware WS, Docker...
  • Security operations
    SIEM, Wazuh, IPS/IDS, NGFW...
  • Networks & secure access
    VPN, VLAN, Tailscale, OPNsense...
  • Exposed Web services
    Apache, Nginx, PHP, MySQL
  • Exposed Mail services
    Postfix, Dovecot, Rspamd
  • Monitoring & logs
    Wazuh, Security Onion, syslog
  • DNS, certificates, SSL/TLS
  • Bash scripting & automation
    Terraform, Ansible, Git
  • Server hardening
  • Backups, DR & BC
  • Synology NAS
  • Service continuity
  • Windows systems
  • Network architecture
  • Switch/router administration
  • File systems management
 
· Automation & tool development

I have regularly used development as a lever for automation, reliability and time savings in my professional environments. Without positioning myself as an application developer, I can create scripts, internal tools and simple interfaces to address concrete needs: operations, reporting, data processing, monitoring, backups or workflow improvement. This pragmatic approach allows me to turn an operational need into a usable, documented and maintainable solution.

  • Bash scripting & automation
  • SQL / MySQL queries
  • Regular expressions
  • HTML, CSS, JavaScript
  • PHP development
  • Internal Web tools
  • Prestashop customization
  • Operations scripts
  • Technical documentation
 
· Graphic design

With a background in advertising communication, I built the first part of my career around graphic production, desktop publishing and digital publishing. This experience gave me a strong culture of production quality, deadline management, client relations and end-to-end project management — skills I later extended into management, automation and digital environments.

Working tools:
  • Adobe Photoshop Expert
  • Adobe Illustrator Advanced
  • Adobe Indesign Expert
  • Adobe Acrobat Advanced
  • Video Editing & Encoding
  • Microsoft Office Suite

Operational management & technical coordination

My career has led me to manage teams, projects and production activities in demanding environments, both in France and internationally. This experience in operational management now strengthens my technical profile: prioritizing requests, organizing work, facilitating follow-up meetings, coordinating different profiles, reporting, and translating business needs into operational solutions. In a systems administration, SecOps or cybersecurity context, it is an asset for working effectively with teams, documenting actions and maintaining a strong service culture.

    · Project management
  • Request prioritization
  • Quality and deadline tracking
  • Procedures and improvement
    · Team coordination
  • Meeting facilitation
  • Task allocation
  • Workload tracking and reporting
    · Service culture
  • Rigor and organization
  • Problem solving
  • Availability and responsiveness

Language skills

· Professional English
English has been part of my professional environment for many years: exchanges with international partners, remote team coordination, trade shows, technical documentation and IT tools. With a TOEIC score of 980, I also passed my CompTIA Security+ and CompTIA CySA+ certifications in English. This practice enables me to work effectively with technical resources, international environments and English-language cybersecurity content.

· Korean
Since my marriage to my South Korean wife in 2005, Korean has been part of my personal and professional environment. I mainly use it during my stays in South Korea and in the context of commercial relationships with Korean clients of my company Laflanelle.

ENGLISH: international professional level, TOEIC 980. CompTIA certifications passed in English
KOREAN: practical basics and personal/professional context

Experience

An operational, technical and entrepreneurial background

My professional path has been built at the crossroads of IT, production, management and entrepreneurship. Initially applied in graphic and marketing environments, my technical skills gradually strengthened around Linux administration, automation, exposed services, networking and service continuity. This long experience has enabled me to develop an operational approach: understanding needs, structuring tools, improving environment reliability, documenting procedures and maintaining useful services under real-world conditions.

LAFLANELLE SASU
LAFLANELLE S.A.S.U.

Founder & President

Infrastructure leadership
& SecOps
Since late 2018
Creation and management of Laflanelle, a company specialized in the international trade of European fabrics and online sales, based in Le Mans, France.

• Development of a multi-channel commercial activity: import/export, e-commerce, marketplaces and international B2B.

• Wholesale export of European fabrics to a mainly South Korean client base, with regular exchanges in English.

• Online retail sales in France and abroad through an e-commerce platform and various European and Asian marketplaces.

• Administration, security hardening and evolution of a production Linux infrastructure supporting the e-commerce activity.

• Operation of exposed services: Web, Mail, DNS, databases, monitoring, backups/DR and service continuity.

• Administration of local network and hosting infrastructure: firewall, VPN, switching, Wi-Fi, servers, VMs and containers.

• Automation, hardening, incident management and formalization of operations procedures.

• Development and adaptation of the e-commerce platform: Prestashop, PHP, MySQL, Smarty, product feeds and internal tools.
DAEBAK SARL
DAEBAK S.A.R.L.

Partner & Managing Director

Since 2023
Creation of a company dedicated to the acquisition and management of furnished tourist accommodation in the Tours area, Centre-Val de Loire.

• Rental activity managed mainly through Airbnb.

• International marketing development, particularly towards Asia, through social networks.
Amandine de Brévelay
Business Project

Sales Agent

2016 - 2018
Sales agent for the Amandine de Brévelay brand, a French home linen manufacturer, on the US and Canadian markets. Activity carried out as part of a business creation project later abandoned following the manufacturer's closure.

• Development of marketing tools and commercial activity in the assigned area.

• Commercial prospecting.

• Participation in various professional trade shows: ICFF, NY NOW in New York, and Maison & Objet in Paris.

• Operations and travel on the Korean market with the local sales agent.
GROUPE LEBLANC SA
Groupe Leblanc S.A.

Marketing Director

Team leadership,
digital tools
& cross-functional projects
2015 - 2016
Marketing Director at Groupe Leblanc, designer and manufacturer of decorative lighting installations in Le Mans, France, with 95 employees at headquarters, 5 subsidiaries abroad and annual revenue of approximately €20M.

• Management of the Marketing & Communication plan for France and international markets: sales materials, trade shows, events, websites, e-commerce, partnerships, sponsorship and video production.

• Management of a 15-person multidisciplinary team: marketing, product design, graphic design, simulation, digital production and international coordination.

• Supervision of the Simulation activity: brochures, videos, AR/VR applications, quality tracking, process industrialization, with 1,200 project files and nearly 20,000 visuals produced per year.

• Development of cross-functional projects with IT, R&D and production: SolidWorks, 3D prototyping, Product Life Manager, ERP and improvement of internal workflows.

• Administration of a Linux server and securing / automation of file exchanges between remote sites via SSH/SFTP.

• Implementation of tools, tracking dashboards and processes to improve quality, traceability, deadlines and team coordination.
GROUPE LEBLANC SA
Leblanc Illuminations S.A.

Graphic & Simulation Manager

Coordination,
internal tools
& technical workflows
2006 - 2015
Graphic & Simulation Manager within Groupe Leblanc in Le Mans, designer and manufacturer of decorative lighting installations, working with sales teams and international subsidiaries.

• Management and coordination of a team of 9 graphic designers, including 5 in Romania: daily facilitation, task allocation, workload tracking and reporting.

• Setup of a remote production studio: workflow organization, work procedures, file exchanges and coordination between sites.

• Administration of Linux servers, Windows workstations and secure workflows between remote sites to support graphic and commercial activity.

• Production of Web & Print sales materials for sales teams, with growth from 160 to 1,200 project files over the period.

• 2D/3D product design, visual simulation, compositing and improvement of graphic production processes.

• Development of productivity and automation tools: Bash, batch & JavaScript scripting, graphic tools and recurring processing tasks.

• Development of internal web applications for planning management and activity tracking: PHP, JavaScript, MySQL.
Keito
Business Project

Online sales & import

2010
Personal project for the import and online sale of Japanese porcelain and ceramic tableware, as part of a business creation project that was not completed.

• Supplier prospection in Japan, particularly in Gifu Prefecture, and in South Korea.

• Graphic design, visual identity and communication materials.

• Design of the showcase website keito.fr.

• Study of import constraints and documentary exchanges with customs services.
Piyou
Freelance

Graphic designer, web designer & IT support

2004 - 2006
Freelance graphic designer, web designer and IT consultant in Martinique and Seoul, directly managing client needs and associated technical environments.

• Consulting in print and web communication.

• Graphic design and desktop publishing for offset and digital printing.

• Photography, digital retouching and preparation of production files.

• Creation of websites in French and English.

• IT support interventions and technical assistance for clients.

• Hosting clients on a private dedicated server and administration of a Linux system.
Cabinet Bernier
Cabinet Bernier

Senior Graphic Designer

2001 - 2004
Senior graphic designer at Cabinet Bernier, a 5-person communication agency in Le Mans, with strong autonomy in client file follow-up and technical production.

• Direct client contact and end-to-end management of projects.

• Graphic design and desktop publishing for offset and web-fed printing.

• Technical responsibility for prepress, quality control and the agency’s CTP workflow.
ETPM
ETPM

DTP Graphic Designer

1997 - 2001
DTP graphic designer at ETPM, a 4-person communication agency in Ballon, dedicated to rural municipalities in Sarthe and local institutional communication materials.

• Direct client contact and full management of assigned projects.

• Graphic design, layout and desktop publishing for offset and digital printing.

• Development of a culture of rigor, short deadlines and reliable production in a small organization.
IMS
Informatique
Marketing System

IT Sales Technician

1996
Technician and salesperson at the I.M.S. computer store in Le Mans, my first professional experience directly focused on hardware, configuration and PC support.

• Sale of PCs, components and computer peripherals.

• Configuration, installation and preparation of client workstations.

• Maintenance, diagnosis and technical assistance on PC computers.
Ecole Interarmées de Sports
French Army

National military service

1994 - 1995
National military service within the Commissariat aux Sports Militaires and the École Interarmées des Sports, in a demanding environment combining discipline, availability and a service mindset.

• Initial assignment to the communication department of the École Interarmées des Sports in Fontainebleau.

• Official driver for the Brigadier General commanding the CSM, at the Bataillon de Joinville in Paris.

• Trusted duties requiring reliability and strict compliance with procedures.

• Awarded the French National Defence Medal, bronze level.

• Obtained an Elite Driver Certificate.

PERSONAL

Demanding personal commitments

Beyond my professional background, several personal activities have strongly shaped the way I work: rigor, responsibility, organization, collective commitment and a taste for learning. Music, radio, the organization of IT events and then aviation have allowed me to evolve in varied, often demanding environments where preparation, communication and reliability are essential.

Les Ailes du Maine Avion
Les Ailes du Maine Avion

Private pilot

Since 2016
Private pilot licence at Les Ailes du Maine flying club, based at Le Mans Arnage Airport - LFRM (72), France.

• Around 100 hours of VFR flying on single-engine piston aircraft: Cessna 150, 152 & 172, APM30 Lion, DR400-108, DR400-160 and Cap 10.

• FCL.055 VFR Level 5 certification: advanced aeronautical English proficiency according to the ICAO framework.

• Demanding practice based on preparation, application of procedures, risk management, decision-making and debriefing.

• Study of IFR flying and personal training on flight simulator.
XLM Informatique & Jeux en Réseau
XLM IT & Network Gaming Association

Founder & President

2000 - 2004
Founder and President of the XLM association in Le Mans, dedicated to promoting IT, network gaming and LAN culture, with around 50 members.

• Responsible for organization, coordination and main network administration of Lanomanies 2002, a national competition qualifying for the World Cyber Games: 250 participants, 300 computers and around 20 servers.

• Organization and network administration of weekly association events: 30 to 50 computers, nearly 200 events over 4 years.

• Administration of dedicated Linux servers, network configuration, technical support for participants and coordination of hardware resources.

• Foundational experience in local networking, servers, availability, event organization and technical incident resolution under real-world conditions.
Vallée FM
Vallée FM
Necropolis Show

Radio Host

1993 - 1994
Host of a weekly radio show dedicated to Metal music on Vallée FM, in Torcy (77), France.

• Nearly 80 shows produced in co-hosting.

• Relations with specialized record labels and preparation of editorial content.

• Interviews with international bands in French and English during concerts in the Paris region.
From Beyond Insanity
[Metal Band]

Guitar & vocals

1991 - 1994
Guitar and vocals in a Death Metal band in Lésigny (77), France.

• Co-composition, writing and collective work around a demanding musical project.

• Several concerts in the eastern Paris region.

Education

My background

Self-taught in many areas, I followed a relatively traditional educational path and obtained a two-year higher education diploma in advertising communication. At the time, I did not really know where these disciplines would take me, having chosen them somewhat by default. It was with the widespread use of computers in advertising and the graphic industry that I found what I truly wanted and enjoyed doing: mastering computers and software to design and carry out creative tasks.
I have always been fascinated by manufacturing processes, especially those of modern printing. I felt the same enthusiasm when I discovered the porcelain industry in Japan at the time I was working on a business creation project in that field.
With a technician’s mindset, what motivates me is understanding how processes fit together to produce a result and putting them into practice. IT became my field of experimentation, and after completing my studies I continued to train myself independently on these subjects.

CompTIA CySA+ Certified
CompTIA Certifications

CySA+

2026
The CySA+ certification was taken in English and obtained in April 2026.

Security Operations
• Analysis of malicious activity indicators, use of monitoring tools, threat hunting, data collection and support for security operations automation.

Vulnerability Management
• Discovery, analysis and prioritization of vulnerabilities, validation of controls, remediation tracking and reduction of technical risk.

Incident Response Management
• Detection, analysis, containment, eradication, recovery, contribution to lessons learned and procedure improvement.

Reporting and Communication
• Documentation of findings, communication with stakeholders, corrective action tracking, metrics, synthesis and prioritization of remediation actions.

CompTIA Security+ Certified
CompTIA Certifications

Security+

2025
The Security+ certification was taken in English and obtained in October 2025.

General Security Concepts
• Security controls, fundamental principles, change management and cryptographic solutions.

Threats, Vulnerabilities and Mitigation
• Threat actors, attack vectors, vulnerabilities, malicious activity indicators, protection measures and social engineering.

Security Architecture
• Secure enterprise infrastructure, cloud, virtualization, data protection, resilience and architecture models.

Security Operations
• Asset management, monitoring, vulnerabilities, identities and access, automation, incident response and data sources.

Security Governance and Oversight
• Governance, risk management, compliance, audits, third-party risk and security awareness.

ETS TOEIC
ETS Global

TOEIC Listening & Reading

2021
The TOEIC Listening & Reading exam was taken in April 2021 in Le Mans.

Score obtained: 980/990, corresponding to advanced professional proficiency in English.

• Listening: 495/495
• Reading: 485/495
• Estimated CEFR level: C1/C2

This level complements regular use of English in international, technical, commercial and aeronautical contexts.
CCI Le Mans Sarthe
Chamber of Commerce and Industry (72)

5 Days to Start a Business

2017
Training program offered by the Le Mans Chamber of Commerce and Industry to structure a business creation project.

Topics covered:
• Entrepreneurial posture and management skills
• Building the business project
• Marketing and commercial strategy
• Legal, tax and social framework
• Financial forecasting and activity management

This training supported the creation of Laflanelle and strengthened my approach to management, prioritization and operational leadership.
Direction Générale de l'Aviation Civile
French Civil Aviation Authority

Private Pilot Airplane Theory Certificate

2017
Aeronautical knowledge examination required to obtain the private pilot airplane licence.

Subjects covered:
• Air law, operational procedures and VFR communications
• Meteorology, navigation and flight preparation
• Human performance, principles of flight and aircraft general knowledge

Successfully passed at the DGAC examination center in Rennes, with a score of 94%. This training strengthens a culture of preparation, procedures, safety and decision-making.
Lycée Champlain
Lycée Champlain (94)

BTS Advertising Communication

1994
BTS in Advertising Communication, a two-year higher education diploma combining communication, marketing, management, economics, law and professional applications.

This training formed the initial foundation of my career in graphic production, client relations, marketing and project management, before my gradual expansion into digital tools, automation and systems.
Lycée Charles-le-Chauve
Lycée Charles Le Chauve (77)

Baccalaureate Mathematics and Natural Sciences (D)

1992
French Baccalaureate D, secondary education diploma specializing in mathematics and natural sciences.

This scientific foundation helped structure my interest in systems, methods, technical logic and understanding complex environments.

Contact

Let’s stay in touch

Feel free to contact me for a professional exchange, an opportunity in Linux systems administration, SecOps, cybersecurity or infrastructure operations.

Lionel Rousseau
Le Mans / Sarthe
FRANCE
Phone
+33 6 85 89 11 86
Email
lionel@rousseau.kr

Professional links

You can also find my profile, certifications and technical portfolio through the following links:

Lionel Rousseau

Operational.
Rigorous.
Curious.
Autonomous.
Service-oriented.