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

At IONOS we manage not only servers, we shape the digital future for over 6.2 million customers worldwide with our solutions. As Europe's leading hosting provider and pioneer for independent cloud solutions, we are building a next-generation infrastructure: from sovereign cloud architectures and high-perform GPU clusters to integrated AI automation tools. What drives us: Digital freedom of choice for Europe and real impact for small and medium-sized enterprises (SMEs) and large enterprises. We work in agile teams, rely on transparent structures and believe that excellence and innovation are only created with real team spirit. Ready for your next step? Become part of IONOS and grow with us. We live a culture of open structures and friendly coexistence, characterized by an unconditional team spirit. Our defense team operates across locations and agile: our team of experts in Berlin and Karlsruhe is growing steadily. To further strengthen this digital shield, we are looking for a personality ready to take responsibility and actively shape the mission of our Defense Platform Services. In this position you are not a classic administrator in the background – you are the guarantee for the accessibility of millions of customers and form our digital shield. The Defense Platform Services team is responsible for ensuring the existence of the digital infrastructure of the entire group. Your mission is the “Active Defense”. You operate in a high-stake environment and control an infrastructure of around 800 components to neutralize real-time threats. As part of an elite unit from Site Reliability Engineers and Network Engineers, you will perform a dynamic cat and mouse game against highly professional attackers. Where others capitulate on massive attack scenarios, start right – because your work decides on the availability of the European web. Tasks Their daily work is the precise response to the permanent threat situation: You balance the high-availability operation of our scrubbing platforms with the continuous development of our defense strategies. Platform design: You manage and optimize complex, Linux-based proxy and defense infrastructures at the highest level. DDoS Mitigation: You actively analyze attack patterns and implement precise countermeasures before failures can occur. Innovation as a weapon: You use state-of-the-art technologies such as AI for log analysis and pattern detection to always be one step ahead and implement new mitigation ideas in the team. Lifecycle Management: You actively shape the operating architecture in an agile DevOps environment and ensure the continuous evolution of our defense systems. Response phase: You participate in the essential readiness (one week per month). This is not a mere duty, but the phase in which you directly intervene as a primary defender to prevent massive outages. Qualifications We are looking for a Linux expert with the “Security gene” – a professional who combines deep technical knowledge with the vigilance of a defender. You understand complex platforms as fortresses that do not tolerate vulnerability. Experience & seniority: You have 3-5 years of well-founded professional experience in the platform operation of large infrastructures. Technical Stack: You are an expert on Linux (Debian/CentOS) and Nginx (Reverse Proxy/WAF). Ideally, you control networking concepts such as BGP, Flowspec and Anycast and use automation tools such as Ansible, Puppet or Python as standard tools. Language competence: In our international environment you communicate fluently in English; German knowledge is a valuable advantage. Benefits Hybrid working model. Flexible working hours through confidence work time. At some locations a licensed canteen and various free drinks. Modern office space with very good transport connection. 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 services, such as sports and health courses. We value diversity and welcome all applications – regardless of gender, nationality, ethnic and social origin, religion, disability, age as well as sexual orientation and identity, physical characteristics, marital status or another non-respected criterion according to applicable law.

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