Cyber Security Engineer — Infrastructure & AI Platform Security (f/m/d)

1&1 IONOS SE; Berlin; Hybrid; EUR 90.000 - 150.000; Vollzeit

Benefits dieser Stelle

Hybrid working model

Flexible hours

Subsidized canteen

Modern office

Employee discounts

Company events

Training & development

Health programs

Zusammenfassung

1&1 IONOS SE is seeking a hands-on security architect to own the security architecture for our provider-side infrastructure and for the AI platforms we run internally. You will ensure these systems operate in a secure, governed, auditable state across multi-tenant environments and act as the SME for platform and agent security.

You will define standards, pressure-test designs, and collaborate with platform and engineering teams across brands to implement robust controls, monitor risk, and

Qualifikationen

• Several years of hands-on infrastructure or platform security experience.
• Deep knowledge of Linux, virtualization, networking, and multi-tenant security.
• Strong background in identity and access management.
• Experience designing and enforcing security standards in heterogeneous landscapes.
• Familiarity with LLM/agent risks and AI safety considerations.

Aufgaben

• Own security architecture standards for provider-side infra and internal AI platforms.
• Define and enforce security baselines across virtualization, containers, DNS, mail, and backups.
• Review designs and serve as escalation point for security questions.
• Drive remediation and risk-based decisions with platform teams.
• Support incident response and post-incident hardening with expertise.

Kenntnisse

Infrastructure security

Linux

Virtualization

Container security

Identity & access

IaC security

AI platform security

Risk analysis

Jobbeschreibung

Tasks

Both halves of this role are about the same underlying question: which systems can reach our most sensitive infrastructure, and under what controls. You will own the security architecture for our provider-side infrastructure layer, and you will be the subject matter expert for the AI platforms and agents we operate internally, making sure they run in a secure, governed, auditable state rather than accumulating quietly as a new class of privileged access.

This is a hands-on expert role. You set standards, pressure-test designs, and work directly with platform and engineering teams across our brands to get them implemented.

Tasks

• Define and maintain security architecture standards and hardening baselines for provider-side infrastructure: virtualization and container platforms, control planes and provisioning systems, DNS, mail infrastructure, and backup and recovery systems.
• Assess and strengthen tenant isolation across shared hosting, virtualization, and container layers, and drive remediation with the responsible platform teams.
• Review infrastructure designs and major changes for security impact, and act as an escalation point for infrastructure security questions from platform, cloud, and brand engineering teams.
• Reduce blast radius on the paths that matter most: privileged access to customer-facing infrastructure, administrative segmentation, secrets handling, and recovery integrity — translated into workable per-brand implementation plans across our heterogeneous platforms.
• Support Cyber Defense, Vulnerability Management, and IT Emergency Management with infrastructure expertise during incidents and post-incident hardening.
• Own the security architecture and baseline standards for the AI platforms we run internally: model gateways and self-hosted models, agent frameworks, assistant integrations, connectors, and retrieval pipelines over internal data.
• Define and enforce how agents are identified, authenticated, and authorized: non-human identity handling, credential and token management, least-privilege tool and system access, and where autonomous action requires a human in the loop.
• Establish what data internal AI systems may access and index, and ensure agent activity is logged, attributable, and reviewable to the standard our regulatory and certification obligations require.
• Run pre-deployment security reviews for new internal AI platforms and agent use cases, at a pace that fits how fast these are being adopted, and keep a picture of where unsanctioned AI usage is emerging.
• Advise the security functions and internal engineering teams on adopting AI safely, including the guardrails that make that adoption defensible.

Qualifications

• Several years of hands-on experience in infrastructure or platform security, ideally at a hosting provider, cloud provider, telco, or comparably large-scale multi-tenant environment.
• Deep practical knowledge of Linux, virtualization and container platforms, networking, and the security properties of multi-tenant infrastructure.
• Strong background in identity and access: privileged access, machine and workload identity, secrets management, authorization models, and infrastructure-as-code security.
• Experience designing and enforcing security standards in a heterogeneous, partly legacy landscape, and getting them adopted by teams you do not manage.
• Working knowledge of how LLM and agent systems are built and operated, and of the risks specific to them: prompt injection through untrusted data, over-scoped tool access, data exposure via retrieval, unlogged autonomous action, model and provider dependency.
• Ability to make and defend risk-based decisions, including blocking a deployment with a clear rationale, and to explain technical risk to non-technical stakeholders.
• Fluent English; German is a strong advantage given our regulatory and public-sector environment.

Nice to have

• Hands-on experience deploying or securing internal AI platforms, agent frameworks, or tool-calling integrations in production.
• Familiarity with NIS2 / BSIG or ISO 27001
• Background in DNS, e-mail infrastructure, or abuse-adjacent platform security.
• Experience in a multi-brand or post-acquisition environment where the same control has to land in several different implementations.
• Security engineering or development background (automation, tooling, scripting).

Benefits

• Hybrid working model.
• Flexible working hours through trust-based working hours.
• At some locations a subsidized canteen and various free drinks.
• Modern office space with very good 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 offers, such as sports and health courses.