GitHub: CesarMH | LinkedIn: cesairemh | Website: cesaire.netlify.app | Email: nohocesar@gmail.com

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Summary

I am a PhD student in Computer Science (expected Dec 2025) with expertise in operating systems, Linux kernel scheduling, performance optimization, and heterogeneous CPU architectures. Skilled in low-level systems programming (C/C++), benchmarking, and prototyping secure and high-performance systems, I have strong experience in leading projects, communicating technical results, and collaborating across teams. Seeking roles as R&D Engineer, Software Engineer, System Developer, or System Architect.

Publications

  • The Impact of Kernel Asynchronous APIs on the Performance of a Kernel VPN - Honore Cesaire Mounah, Djob Mvondo, Julia Lawall, Yerom-David Bromberg - Proceedings of the 18th ACM International Systems and Storage Conference (SYSTOR ‘25), 2025. DOI

    Abstract: Linux kernel VPNs suffer from severe performance degradation under high load due to execution order inversion (EoI), a phenomenon where packet recombination functions preempt earlier pipeline stages. This leads to severe latency spikes and throughput reductions. We investigate kernel threads and workqueues as alternative kernel asynchronous APIs to address these limitations, achieving up to a 4.7x increase in throughput while reducing tail latency by 65%. These results demonstrate the importance of selecting appropriate kernel asynchronous APIs for kernel-level network applications.

Work Experience

Ph.D. Researcher in Computer Science @ Inria Rennes

Dec. 2022 – Present

Topic: Understanding Linux Scheduling Bottlenecks
Supervisors: Prof. David Bromberg (University of Rennes), Dr. Julia Lawall (Inria Paris), Dr. Djob Mvondo (University of Rennes)

Optimizing Linux Kernel Networking (WireGuard VPN)

  • Investigated performance bottlenecks in the WireGuard VPN module, identifying Execution Order Inversion (EoI) as the root cause of a 5× throughput drop
  • Designed and implemented asynchronous kernel APIs (kernel threads, workqueues) to resolve the bottleneck
  • Impact: Achieved 4.7× higher throughput and 65% lower tail latency, directly improving real-world VPN performance

Energy Efficiency of Heterogeneous CPUs

  • Built an automated benchmarking framework to evaluate Intel heterogeneous CPUs (P-cores/E-cores) across DVFS governors and workload types
  • Delivered actionable insights for scheduler design and CPU tuning, balancing performance and energy efficiency

Core responsibilities: End-to-end project ownership (design, prototyping, benchmarking), Linux kernel instrumentation, experimental automation, and dissemination (publications, conference talks, technical reports).

Research Intern @ IRISA Rennes

Jun. 2022 – Sept. 2022

Supervisors: Prof. David Bromberg, Dr. Djob Mvondo (University of Rennes)

Scalability Evaluation of WireGuard VPN

  • Designed and executed large-scale experiments to test WireGuard under high-load scenarios
  • Skills gained: Experimental design, large-scale VPN deployment, automated benchmarking, data-driven performance analysis

Network-based Stalkerware Detection

  • Evaluated the effectiveness of TinyCheck, a network-based stalkerware detection tool, against commercial anti-malware solutions
  • Extended TinyCheck for deployment as a Function-as-a-Service (FaaS) on an OpenFaaS platform
  • Skills gained: Android automation and testing, FaaS deployment, network security evaluation

Education

2022 - present: PhD at INRIA, University of Rennes, France

2017 - 2022: Engineering Degree in Computer Science, National Advanced School of Engineering, Yaounde, Cameroon

Technical Skills

Programming Languages: C/C++ (expert), Python (proficient), Go, Bash, JavaScript, Assembly

Systems & Infrastructure: Linux Kernel Development (scheduling, networking, drivers), FreeBSD, Docker, Kubernetes, CI/CD (GitHub Actions, Jenkins)

Performance & Optimization: Performance profiling (perf, ftrace, eBPF), benchmarking frameworks, scalability testing, memory optimization, NUMA awareness

Networking & Security: VPN technologies (WireGuard, OpenVPN), TCP/IP stack, network performance tuning, security analysis, traffic monitoring

Development Tools: Git, GDB, Valgrind, QEMU, FUSE, WebAssembly, automated testing frameworks, build systems (Make, CMake)

Languages

  • French
  • English