Kuaishou System Software Team: Architecture, Innovations, and Performance Optimizations

System software serves as the foundation of software architecture, bridging hardware and higher‑level software; Kuaishou's system software team has spent four years building innovations across Java coroutines, compiler optimizations, and OS improvements.

Core Value and Challenges – System software enhances server resource utilization, improves performance by 30‑50%, and ensures business stability, but scaling introduces stricter constraints, requiring deep low‑level expertise and precise problem targeting.

"Four Horizontal Four Vertical" Architecture – The team established a layered tech stack: JVM runtime, C++ build system, OS layer, and micro‑architecture layer, each critical for stability and performance.

JVM Innovations – Developed Java 17 transparent coroutines (non‑intrusive, 30% throughput gain) and a JVM checkpoint feature that cuts startup time from 150 s to 80 s and reduces launch CPU utilization from 23% to 5%.

Compilation Techniques – Integrated BOLT, AutoFDO, LTO, and other optimizations, achieving 10‑13% overall performance gains and 4‑8% latency reductions; combined BOLT + AutoFDO with a Match+Infer solution raised optimization impact from 8% to 12%.

Kernel Isolation & Resource Scheduling – Built a custom kernel for cloud‑native scenarios, introducing online/offline scheduling trees, dual‑queue QoS, and LLC isolation, which doubled machine utilization while protecting online services.

Extreme Performance Optimizations – Applied CPU‑level IPC, utilization, and complexity reductions, refined a critical size() function to cut its CPU share from 8.4% to 2.5% and doubled overall performance, saving thousands of servers.

In summary, the team’s breakthroughs in system software have delivered substantial cost savings, performance improvements, and a robust foundation for Kuaishou’s large‑scale services, while continuing to invite talent to further advance these technologies.