This article discusses the challenges of optimizing mobile network performance at Layer 4 of the networking stack. It explains how TCP Congestion Control algorithms work and their limitations on mobile networks, which are more susceptible to interference resulting in packet loss. The author provides several suggestions for improving performance for visitors connecting via mobile networks, including upgrading your kernel, enabling Proportional Rate Reduction (PRR), adjusting initcwnd and initrwnd values, and setting tcp_slow_start_after_idle=0. Additionally, the article highlights some upcoming features in newer Linux kernels that may further improve mobile network performance.