Senior Linux Kernel Developer

Nucleon Security is a fast-growing Deeptech startup building next-generation cybersecurity solutions powered by artificial intelligence, designed to stop the most advanced threats. With operations across Europe and Africa, we proudly deliver 100% sovereign technology trusted by organizations of all sizes - from agile startups to global enterprises. Our expertise? Protecting endpoints across all environments. Automating the detection of complex attacks. Empowering security teams with intuitive, high-performance platforms. Our ambition is clear: become a global leader in cyber resilience, enabling organizations to anticipate, detect, and contain threats autonomously and securely. Your mission As a Windows Kernel & Agent Developer at Nucleon Security, you will design, develop, and maintain the kernel-mode drivers and user-mode components that form the core of our cybersecurity agent. You will :

Develop and maintain Windows kernel drivers (minifilter, WFP, callbacks, etc.). Build user-mode C services that communicate with the drivers to process events, apply policies, and manage the agent. Implement monitoring and protection features across file, network, process, and registry layers. Integrate advanced anti-tampering mechanisms, with the possibility of adding an ELAM driver later. Ensure stability, compatibility, and robustness across multiple Windows versions and builds. Troubleshoot complex low-level issues, including kernel crashes, BSODs, race conditions, and performance bottlenecks. Contribute to automation and validation for driver and agent releases.

Your key objectives

Build stable, high-performance kernel drivers - Reliable drivers validated across supported Windows versions Strengthen agent self-protection - Advanced anti-tampering, resistance to manipulation, future ELAM support Provide deep system visibility- Accurate telemetry and interception across core OS subsystems Advance low-level R&D - Evaluate and improve interception/monitoring techniques (minifilter, WFP, callbacks, ETW) Improve reliability & troubleshooting - Strong crash analysis, debugging, and automated regression testing

Strong proficiency in C and low-level systems development. Solid understanding of Linux internals: memory management, scheduling, syscalls, namespaces, cgroups, kernel subsystems. Experience developing and maintaining kernel modules (LKM). Hands-on experience with eBPF (kprobes/uprobes, tracepoints, maps, CO-RE, BPF loaders). Experience building user-mode components interacting with low-level modules (netlink, ioctl, ring buffers, perf buffers, shared memory). Strong capability in debugging low-level issues: kernel crashes, deadlocks, race conditions, performance bottlenecks, memory leaks/corruption. Knowledge of network stack internals and system-level interception techniques. Experience with multiple Linux distributions (Debian, Ubuntu, RHEL/CentOS/Rocky, SUSE). Good understanding of secure coding practices, kernel hardening, and defense against kernel-level attacks. Experience with automated testing (CI/CD), kernel versioning, and validating features across multiple OS environments is a strong plus. 3+ years of professional experience: In kernel or low-level systems development. Security expertise: Experience in security/cybersecurity is a strong plus. Strong problem-solving skills: Autonomy and ability to handle complex technical challenges. Collaborative mindset: Team player with knowledge-sharing attitude. Technical English: Proficient in documentation and community interactions.

This role is for you if… You excel at low-level development and enjoy tackling complex challenges within OS internals. You have strong expertise in Linux kernel development and want to work on security-critical components. You are autonomous, rigorous, and motivated by producing high-quality technical work. You thrive in an environment where innovation, research, and continuous improvement are core values.