Linux - System Administrator (f/m/d) Defense Products

IONOS; Karlsruhe; Hybrid; EUR 70.000 - 95.000; Vollzeit

Benefits dieser Stelle

Hybrid working model

Flexible hours (trust-based)

Canteen subsidized and free drinks

Modern office with good commute

Employee discounts and events

Zusammenfassung

IONOS is seeking a Specialist in our Defense squad in Karlsruhe/Berlin to shield our cloud and hosting platforms from daily DDoS and advanced cyber threats. You’ll work with site reliability engineers and network engineers within a distributed, international team, deploying modern AI-driven log analysis and high-volume telemetry.

You will manage a large Linux-based proxy infrastructure, participate in on-call rotations, and evolve CI/CD pipelines using Docker and Kubernetes to stay ahead of

Qualifikationen

• Expert-level proficiency in managing complex, distributed Linux environments.
• Proven experience configuring Nginx as a reverse proxy or Web Application Firewall (WAF).
• Practical knowledge of BGP, Flowspec, and Anycast routing.
• A passion for eliminating repetitive tasks through Ansible, Puppet, and Python.
• Several years of experience in the administration of complex, distributed Linux systems.
• Proven experience in configuring and operating Nginx as a reverse proxy or web application firewall.
• Hands-on experience with the deployment of BGP, Flowspec, and Anycast routing on Linux systems and network routers.
• Strong passion for automation using tools like Ansible, Puppet, and Python to eliminate repetitive manual tasks.
• Strong analytical skills to evaluate DDoS attacks, implement effective countermeasures, and continuously develop our defense platforms.
• Initial experience with technologies such as Docker, Kubernetes, ClickHouse, or the ELK Stack is beneficial.
• Like us, you are a strong advocate for Open Source, especially Linux.

Aufgaben

• Active Defense & DDoS Mitigation: Administer and troubleshoot scrubbing platforms and a complex, large-scale proxy infrastructure.
• Architectural Density & Operational Excellence: Manage the lifecycle of 800+ Linux-based components within a highly available infrastructure.
• Innovation & Data-Driven Defense: Leverage ELK Stack and ClickHouse for log analysis and pattern detection.
• Lifecycle & Pipeline Management: Develop and optimize CI/CD pipelines; evaluate and integrate Docker and Kubernetes to keep defense architecture ahead.

Kenntnisse

Linux administration

Nginx / WAF

BGP / Flowspec / Anycast

Automation: Ansible / Puppet / Python

Docker / Kubernetes

ELK Stack / ClickHouse

Tools

Nginx as reverse proxy or WAF

Git / CI-CD pipelines

Jobbeschreibung

At IONOS, the leading European provider of cloud infrastructure, cloud services and hosting services, you will work together with a wide range of teams. We are characterized by open structures, a friendly working culture and flat hierarchies with a strong team spirit. We firmly believe that work and fun are compatible, and offer you the right environment for this. Our constant growth means that we are always looking for new colleagues. Become part of IONOS and grow with us.

Join our highly motivated team of experts dedicated to combating cybersecurity threats. As a System Administrator, you will plan and operate our cutting-edge defense platforms alongside site reliability engineers and network engineers. These platforms are crucial for protecting our hosting products and infrastructure, encompassing classic DDoS mitigation, modern Web Application Firewalls (WAF), Zero Trust strategies, and our Content Delivery Network (CDN). We foster a culture that highly values creative ideas, agile working methods, initiative, and participation.

As an Specialist in our Defense squad, you act as a vital shield against daily DDoS and sophisticated cyber attacks. You are the first line of defense, dedicated to neutralizing threats through technical mastery and proactive mitigation.

We are hiring for this role in Karlsruhe and/or Berlin. You will join a distributed, international Defense Platform Services team of approximately 8–9 experts. You will work within specialized squads for Operations, SRE, and NRE to provide comprehensive protection for the group's infrastructure across Germany and beyond.

Tasks

• Active Defense & DDoS Mitigation: Administer and troubleshoot scrubbing platforms and a complex, large-scale proxy infrastructure. You will engage in the "cat and mouse game" of fighting attacks in real-time—identifying, washing, and neutralizing malicious traffic to protect core cloud and fiber services.
• Architectural Density & Operational Excellence: You will manage the lifecycle of 800+ Linux-based components within a highly available infrastructure. To maintain 24/7 group-wide protection, this role requires a mandatory on-call service rotation of one week per month, ensuring immediate response to high-priority network threats.
• Innovation & Data-Driven Defense: We leverage modern AI tools for log analysis and pattern detection. You will bring creative ideas to the table, utilizing the ELK Stack and ClickHouse to manage high-volume telemetry, identify attack signatures, and devise advanced mitigation strategies.
• Lifecycle & Pipeline Management: Develop and optimize CI/CD pipelines in an agile DevOps environment. You will evaluate and integrate new technologies—including Docker and Kubernetes—to ensure our defense architecture remains lean, efficient, and ahead of evolving industry threats.

Qualifications

• Expert-level proficiency in managing complex, distributed Linux environments.
• Proven experience configuring Nginx as a reverse proxy or Web Application Firewall (WAF).
• Practical knowledge of BGP, Flowspec, and Anycast routing.
• A passion for eliminating repetitive tasks through Ansible, Puppet, and Python.
• Several years of experience in the administration of complex, distributed Linux systems.
• Proven experience in configuring and operating Nginx as a reverse proxy or web application firewall.
• Hands-on experience with the deployment of BGP, Flowspec, and Anycast routing on Linux systems and network routers.
• Strong passion for automation using tools like Ansible, Puppet, and Python to eliminate repetitive manual tasks.
• Strong analytical skills to evaluate DDoS attacks, implement effective countermeasures, and continuously develop our defense platforms.
• Initial experience with technologies such as Docker, Kubernetes, ClickHouse, or the ELK Stack is beneficial.
• Like us, you are a strong advocate for Open Source, especially Linux.

Benefits

• Hybrid working model.
• Flexible working hours through trust-based working hours.
• Subsidized canteen and various free drinks at select locations.
• Modern office space with excellent public transport connections.
• Various employee discounts for activities and products.
• Employee events such as summer and winter parties, as well as workshops.
• Numerous training and development opportunities.
• Various health offerings, such as sports and wellness courses.

About IONOS

IONOS is the leading European digitalization partner for small and medium-sized businesses (SMB). The company serves around six million customers and operates across 18 markets in Europe and North America, with its services being accessible worldwide. With its Web Presence & Productivity portfolio, IONOS acts as a 'one-stop shop' for all digitalization needs: from domains and web hosting to classic website builders and do-it-yourself solutions, from e-commerce to online marketing tools. In addition, the company offers Cloud Solutions to enterprises who are looking to move to the cloud as their businesses evolve.

We value diversity and welcome all applications - regardless of, for example, gender, nationality, ethnic or social origin, religion, disability, age as well as sexual orientation and identity, physical characteristics, marital status or any other irrelevant factor subject to applicable law.