Backend Infrastructure Engineer Graduate (AI Development) - 2025 Start (PhD)

TikTok is the leading destination for short-form mobile video. At TikTok, our mission is to inspire creativity and bring joy. TikTok's global headquarters are in Los Angeles and Singapore, and its offices include New York, London, Dublin, Paris, Berlin, Dubai, Jakarta, Seoul, and Tokyo.

Why Join Us
Creation is the core of TikTok's purpose. Our platform is built to help imaginations thrive. This is doubly true of the teams that make TikTok possible.
Together, we inspire creativity and bring joy - a mission we all believe in and aim towards achieving every day.
To us, every challenge, no matter how difficult, is an opportunity; to learn, to innovate, and to grow as one team. Status quo? Never. Courage? Always.
At TikTok, we create together and grow together. That's how we drive impact - for ourselves, our company, and the communities we serve.
Join us.

About the team
We are a team of engineers and researchers dedicated to building and optimizing the foundation of TikTok's backend infrastructure. Our focus is on data access control, backend traffic control, and data center layout, ensuring a secure, efficient, and scalable architecture for TikTok's global operations. We also aim to balance cost efficiency, performance optimization, and security across TikTok's massive-scale infrastructure by leveraging advanced algorithms, real-time traffic analysis, and distributed system strategies.

Our team is passionate about tackling complex large-scale challenges in backend infrastructure, security, and distributed systems. We thrive on turning cutting-edge research into practical, high-impact solutions that power TikTok’s growth and user experience.

Responsibilities
- Research, explore, and implement cutting-edge LLM (Large Language Models), RL (Reinforcement Learning), and other AI-driven techniques to solve emerging engineering challenges and drive innovation in infrastructure optimization.
- Research and build agents to enhance development productivity and code quality, specifically with tasks such as feature development, test automation, code optimization, etc.
- Analyze and optimize large-scale TikTok backend codebase to reduce operational costs and enhance execution efficiency, ensuring optimal system performance.
- Analyze online traffic patterns and develop optimized traffic scheduling solutions to improve data center's cost-effectiveness, stability and efficiency
- Turn the latest algorithm research results into scalable, and highly complicated systems in TikTok's real-world engineering environments.
- Design and build supporting/debugging tools as needed.