Systems Software Engineer

About the role

Roblox is seeking a Systems Software Engineer to join the Engine Networking Team, which is responsible for ensuring seamless communication of game state across millions of concurrent players worldwide. In this position, you will play a critical role in enabling players to experience the Roblox platform as a nearly synchronous virtual world, regardless of their geographic location or device type. Your work will directly impact how tens of millions of daily users explore, create, play, learn, and connect with friends in immersive three-dimensional digital experiences. This role offers the opportunity to tackle unique technical challenges at massive scale while contributing to a platform that aims to connect a billion people through optimism and civility. You will be working at the intersection of game engine development and high-performance networking, helping to shape the future of human interaction in digital spaces.

Key facts

What you'll do

• Design, develop, and optimize user-space network stack components to address challenges related to scalability, performance optimization, latency reduction, and throughput maximization in client-server architectures
• Engineer solutions that enable real-time communication across a massive multithreaded distributed system connecting millions of users simultaneously around the globe
• Collaborate with cross-functional teams to ensure network systems function seamlessly across all supported device platforms, including desktop computers, mobile phones, and gaming consoles
• Analyze and improve network exchange timing down to the millisecond level, identifying where time is being consumed and implementing strategies to eliminate inefficiencies
• Work directly within the game engine codebase to integrate networking functionality with other core engine systems and ensure optimal performance
• Develop and maintain systems-level C++ code with deep attention to how the CPU executes operations involving smart pointers, templates, virtual functions, and both structured and raw memory blocks
• Investigate and resolve complex issues related to Linux networking and common network protocols to ensure reliable communication across the platform
• Contribute to open-source networking projects and integrate relevant technologies into the Roblox platform where appropriate
• Profile and optimize code at the operating system level, understanding precisely what happens when specific operations are executed
• Participate in code reviews, architectural discussions, and technical planning sessions to continuously improve the quality and reliability of network systems
• Monitor and analyze network performance metrics to identify bottlenecks and opportunities for improvement across the entire player experience
• Document technical designs, implementation details, and best practices to support team knowledge sharing and onboarding of new engineers

Requirements

• Minimum of four years of professional experience in game networking, specifically within a game engine or game studio environment
• Demonstrated expertise working on high-performance user-space network stacks, with proven ability to solve problems related to scale, performance, latency, and throughput
• Strong systems-level programming proficiency in C++ with deep understanding of low-level CPU operations and memory management
• Hands-on experience with Linux networking environments and solid knowledge of common network protocols and their implementations
• Track record of contributing to large-scale multithreaded distributed systems that serve millions of concurrent users
• Comprehensive understanding of game engine architecture and the specific networking requirements of real-time multiplayer experiences
• Ability to analyze and optimize network timing at the millisecond level with a keen eye for identifying and eliminating performance waste
• Strong understanding of operating system internals and what occurs at the system level when code is executed
• Experience developing software that runs across multiple device platforms including desktop, mobile, and console environments

Nice to have

• Active involvement in open-source networking projects or communities with a passion for collaborative development
• Experience with custom transport protocol development or optimization beyond standard TCP and UDP implementations
• Background in developing or optimizing netcode for massively multiplayer online games or similar large-scale interactive applications
• Familiarity with modern game engine architectures such as Unreal Engine or Unity and their networking subsystems
• Knowledge of emerging networking technologies and standards relevant to real-time interactive applications
• Experience with network simulation, testing frameworks, or chaos engineering for distributed systems

Skills & tools

• C++ programming at the systems level with emphasis on performance optimization
• User-space network stack development and optimization
• Linux networking and system administration
• Common network protocols including TCP, UDP, and custom transport layers
• Multithreaded programming and distributed systems architecture
• Game engine development and integration
• Performance profiling and optimization tools
• Memory management and low-level CPU operations
• Cross-platform development for desktop, mobile, and console devices
• Open-source software development practices

Practical notes

• This position is based at Roblox headquarters in San Mateo, California, with a hybrid work arrangement requiring onsite presence on Tuesday, Wednesday, and Thursday each week
• Monday and Friday office attendance is optional unless specifically noted for particular projects or meetings
• The stated salary range represents the starting base pay, with actual compensation determined by factors including professional background, training, work experience, location, business needs, and market demand
• In some circumstances, the actual salary may fall outside the expected range based on these factors
• The pay range is subject to modification in the future based on market conditions and company policies
• All full-time employees receive equity compensation in addition to base salary
• Comprehensive benefits package is provided to all full-time employees
• Roblox maintains equal employment opportunity policies and prohibits discrimination based on race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by applicable laws
• Reasonable accommodations are available for candidates with qualifying disabilities or religious beliefs during the recruiting process
• Candidates should be aware of the current limitations regarding certain U.S. visa categories and H-1B sponsorship before applying