Lionel Debroux
Sysadmin Software Developer at Atos Worldgrid
Greater Grenoble Metropolitan Area France
Summary
🤩
Rockstar🎓
Top SchoolLionel Debroux is a pragmatic software developer with 21 years of experience specializing in C/C++ systems, Linux administration, and security-focused tooling. Based in the Grenoble area, he blends hands-on embedded and low-level work—contributing optimizations to the NumWorks calculator OS and Memtest86+ hardware-facing code—with production sysadmin skills across Debian/Ubuntu, RHEL, Proxmox and TrueNAS. At Atos Worldgrid he combines C++ development, Git-driven migrations and custom OS image automation with periodic security hardening and incident prevention. His open-source contributions show a knack for resource-constrained optimization (16-bit downsizing, header refactors to speed builds) and deep hardware knowledge (SMBIOS, SPD decoding). Outside work he pursues small-scale security research via fuzzing and maintains libre tooling for niche hardware like TI calculators, evidencing a long-standing commitment to durable, community-focused software.
22 years of coding experience
3 years of employment as a software developer
Master 2 Pro Génie Informatique Computer science, Master 2 Pro Génie Informatique Computer science at Université Joseph Fourier (Grenoble I)DEUG MIAS Computer science, DEUG MIAS Computer science at Pierre and Marie Curie University
English
Github Skills (18)
c-language10
system-programming10
hardware-interface10
memory-management10
bios10
c1110
hardware10
c1710
performance-optimization10
sys10
embedded10
cprogramming-language10
optimization10
operating-system10
architecture9
Programming languages (16)
Github contributions (5)
memtest86plus/memtest86plus
Feb 2022 - Jan 2023
Official repo for Memtest86+
Role in this project:
System Engineer / Low-Level Developer
System Engineer / Low-Level DeveloperContributions:134 reviews, 44 commits, 32 PRs in 11 months
Contributions summary:Lionel contributed to the low-level system code of Memtest86+, focusing on hardware interaction and system-level optimizations. Their work includes adding CLI arguments for enabling tracing, optimizing interrupt handler performance using compile-time string concatenation, and declaring functions static to reduce code size. Additionally, the user implemented SMBIOS parsing, fixed out-of-bounds access issues, and added SPD (Serial Presence Detect) decoding for SDRAM to improve memory information reporting. They demonstrate a strong understanding of system architecture and hardware details.
x86x86-64
numworks/epsilon
Sep 2018 - Sep 2019
Modern graphing calculator operating system.
Role in this project:Embedded Systems Engineer / Software Architect
Embedded Systems Engineer / Software ArchitectContributions:21 commits, 6 PRs, 59 comments in 11 months
Contributions summary:Lionel's primary contribution involves optimizing and refactoring the operating system for a graphing calculator. This includes enhancing code performance by moving methods to headers for compiler optimization, and reducing memory usage by using 16-bit values. Furthermore, the user split a large header file into smaller, more manageable ones to reduce build times. The changes indicate an in-depth understanding of the system architecture and optimization techniques for resource-constrained environments.
operating-system
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