Marek Majkowski explores techniques for optimizing UDP application latency on Linux systems, focusing on modern features of multiqueue network interface cards (NICs). The experiment involves two Linux hosts using a UDP echo protocol to measure round-trip time (RTT), with optimizations including the SO_BUSY_POLL socket option, userspace busy polling, and CPU pinning to specific cores to reduce latency. The use of Receive Side Scaling (RSS), flow steering, Transmit Flow Steering (XFS), and Receive Flow Steering (RFS) are discussed to enhance packet handling across CPUs. Advanced methods such as disabling interrupt coalescing and leveraging hardware support like Accelerated RFS on Solarflare NICs, as well as low-level tweaks to NIC settings, further minimize latency. The document highlights the trade-offs between latency and throughput and concludes with recommendations for optimizing packet delivery in high-performance environments.