Applications are invited for an exciting PhD position in systems security with the MadriSec group (GitHub) at the IMDEA Software Institute. The selected candidate will work closely with Prof. Georgios Portokalidis on securing operating systems and systems software. The PhD researcher will work at the intersection of operating systems, compilers, software security, and software\-hardware co\-design, developing new systems and toolchains with real\-world impact. The research will focus on advancing systems security through several complementary directions, including: * Vulnerability mitigation – understanding, analysing, and mitigating security vulnerabilities in systems software. * Software hardening through instrumentation – designing and implementing runtime protections and enforcement mechanisms. * Code analysis – developing techniques to analyse, understand, and secure complex software systems. * Software–hardware co\-design for security – exploring coordinated approaches across the software and hardware stack. ### **Who should apply?** Applicants must possess: * Strong programming and tool\-building skills, demonstrated through prior projects (e.g. open\-source repositories, research prototypes, compilers, analysis tools). Applicants are encouraged to provide links to relevant work. * Experience in at least three of the following areas: + The Linux operating system and its internals. + Programming in C/C\+\+. + Extending or working with compiler toolchains (e.g. Clang/LLVM). + Knowledge of computer architecture and its interaction with software. * A strong interest in systems and software security research, and motivation to pursue a research\-driven PhD. * An MSc degree in Computer Science or a closely related field, completed within the last three years (within two years for non\-EU citizens). ### **Why IMDEA Software?** Ranked among Europe’s leading research institutes in Computer Security, IMDEA Software offers: * A collaborative, international environment in Madrid’s Montegancedo Science \& Technology Park. * Competitive salary, excellent public healthcare, unemployment and retirement benefits. * Travel support for research. * English as the working language (no Spanish required). ### **Dates** Start date: asap. Application deadline: **13 February 2026**. Applications are reviewed immediately and until the position is filled. ### **How to apply?** Submit your application at https://careers.software.imdea.org/. Choose option **PhD Student** and use reference code **2026\-01\-phd\-ossec**. The recruitment process follows IMDEA Software Institute’s OTM\-R Policy (Open, Transparent and Merit\-based Recruitment). ### **Questions?** Contact Georgios Portokalidis: .