Senior Pentester (m/f/d)

About the Company -

Rakuten empowers through technology.

Rakuten Symphony Deutschland operates a nationwide mobile network based on the Rakuten Communications Platform (RCP). RCP is a fully virtualized, cloud-native telco platform developed across global hubs. Through our Network Innovation Lab, we partner with research organizations and start-ups to advance OpenRAN technologies and build the autonomous networks of the future.

We are looking for an experienced pentester to help grow our team of ethical hackers to find and help fix security issues across the mobile network end-to-end. This is your opportunity to help build security into large-scale mobile network.

Hacking is driven by creative thinking and challenging the status quo. We believe the industry thrives on diverse perspectives and backgrounds. We look beyond conventional degrees, prioritizing raw talent, passion, and impact. We embrace flexibility, an open mind, and a collaborative environment.

Responsibilities:

• Conduct advanced security assessments (pentesting and red teaming) on the software, hardware, and cloud components of the network and Rakuten Symphony platform
• Manage the lifecycle of identified vulnerabilities, working closely with Release Management to drive effective remediation
• Collaborate with fellow security engineers on complex, deeply technical security challenges
• Engage with internal technology teams and external vendors to drive a security-first culture
• Contribute to system architecture designs and help the broader community build more secure technologies
• Design, build, and maintain innovative tools to automate security assessments and improve detection capabilities

Requirements:

• Several years of experience in penetration testing, including Red Team engagements
• Relevant certifications (e.g., OSCP or equivalent)
• Strong proficiency in source code review; capable of identifying security flaws in languages such as Python, Java, and C/C++
• Experience in cloud infrastructure, including Red Hat Linux, Kubernetes
• Specialized knowledge in at least one relevant domain (e.g., cloud-native security, protocol/radio hacking, telco infrastructure, or hardware security) and a willingness to expand your expertise into new domains
• Strong scripting and automation skills
• A remediation mindset: you enjoy the process of collaborating with developers to fix complex issues.

Work Location: Düsseldorf or Ratingen, with flexible remote work options.