CloudLinux is hiring a Senior/Staff C Engineer to provide technical leadership in optimizing web performance and our core CloudLinux features. You will work deeply on web server performance, request handling, PHP solutions, and our resource limitation and isolation systems.

What You'll Do

Optimize web performance by developing and implementing solutions to improve web server efficiency and request handling.
Work with web servers (Nginx, Apache, LiteSpeed) by configuring, optimizing, extending, and developing modules.
Optimize PHP handlers and web request processing.
Architect scalable, high-performance web systems and infrastructure solutions.
Implement security measures to protect against web attacks and strengthen web server security.
Optimize MySQL and MariaDB databases, including queries, performance, and administration.
Support and optimize PHP solutions and infrastructure.
Maintain and enhance LVE features like resource limits, CPU throttling, memory limits, and I/O limits.
Maintain and enhance MySQL Governor for database resource limitation and optimization.
Maintain and enhance CageFS for file system isolation and user isolation mechanisms.
Design and implement new resource limiting mechanisms and improvements to existing limit systems.
Create new isolation technologies and enhance existing isolation mechanisms for better security and performance.
Design scalable, high-performance system-level solutions for resource management and isolation.
Work deeply with Linux system calls and low-level system programming.
Lead technical initiatives and make proposals that change solutions and technical direction.
Optimize system performance through profiling, benchmarking, and algorithmic optimization.
Make data-driven decisions using benchmarking, profiling, and measurements.
Contribute to upstream solutions and open-source projects.
Leverage AI tools to enhance productivity and improve solutions.
Mentor and coach engineers, conduct technical reviews, and establish engineering best practices.
Collaborate with cross-functional teams to define technical strategy and roadmaps.
Troubleshoot complex production issues across web performance, limits, isolations, and system-level functionality.

What We're Looking For

6+ years of professional software engineering experience in C.
Experience holding senior/staff/principal engineering positions.
Expert-level proficiency in C programming.
Experience with web performance projects or solutions for optimizing web performance.
Deep knowledge and experience with Nginx, Apache, and/or LiteSpeed, including developing C modules and extensions.
Experience with PHP handlers and web request processing optimization.
Deep experience with system-level programming and low-level system optimization.
Understanding of Linux kernel internals, system calls, and system-level programming concepts.
Experience with resource limits, cgroups, namespaces, or similar resource management and isolation technologies.
Comprehensive understanding of Linux system administration, internals, kernel architecture, and optimization.
Strong understanding of security basics for web attacks, isolation mechanisms, and Linux security.
Solid experience with MySQL and MariaDB, including optimization and administration.
Proven ability to use benchmarking and measurements to validate and prove technical decisions.
Experience contributing to open-source projects or upstream codebases.
Experience developing new Apache/Nginx/MySQL/PHP modules/plugins and contributing to open-source existing ones.
Strong understanding of the network stack, particularly TCP/IP and HTTP.
Ability to design scalable, maintainable, and reliable systems at both web infrastructure and system levels.
Technical leadership experience: mentoring engineers, conducting technical reviews, and driving engineering best practices.
Knowledge of CI/CD pipelines and DevOps practices.
Excellent communication skills for articulating complex technical concepts to technical and non-technical audiences.
Strong collaboration skills and ability to work effectively in a remote, distributed team.
Experience with POSIX programming in C.
Experience with thread programming in C.
Hands-on experience with profiling tools like perf, gprof, valgrind.
English at an upper-intermediate level or higher.

Technical Stack

Languages: C
Web Servers: Nginx, Apache, LiteSpeed
Database: MySQL, MariaDB
Runtime: PHP
Platform: Linux
APIs: POSIX
Tools: perf, gprof, valgrind

Team & Environment

You will join our Engineering team.

Benefits & Compensation

A focus on professional development.
Interesting and challenging projects.
Fully remote work with flexible working hours.
Paid 24 days of vacation per year.
10 days of national holidays.
Unlimited sick leaves.
Compensation for private medical insurance.
Co-working and gym/sports reimbursement.
Budget for education.
Opportunity to receive a reward for the most innovative idea that the company can patent.