Modern datacenters must handle an ever-growing array of real-time and data-intensive workloads, such as interactive web services and AI models, that demand both low latency and high throughput. However, traditional operating systems introduce significant I/O overhead, degrading performance and reducing efficiency. A common solution is to let applications directly communicate with hardware, bypassing the operating system altogether. While this greatly improves performance, it sacrifices compatibility with existing software and requires operators to dedicate hardware to each application, ultimately reducing overall resource utilization.

In this talk, I will present a new datacenter operating system design that achieves high I/O performance without making these tradeoffs. First, I will introduce Shenango, which allows applications that directly access hardware to efficiently share CPU cores with other tasks, maintaining high performance without requiring dedicated resources. Next, I will discuss Caladan, a system that prevents performance degradation by managing interference among co-located applications. Finally, I will describe Junction, a library operating system that extends these benefits to unmodified applications, unlocking higher performance and efficiency across diverse workloads.