Network

In 2006, Amazon discovered something that would reshape how the industry thinks about performance: every 100 milliseconds of latency cost them 1% in sales. That same year, Google found that adding just 500 milliseconds of delay to search results caused a 20% drop in traffic. These weren’t hypothetical concerns—they were measured impacts on real revenue. The physics of the internet imposes hard constraints. Light travels through fiber optic cable at roughly two-thirds its speed in vacuum—approximately 200,000 kilometers per second. A round trip from New York to Singapore covers about 30,000 kilometers of fiber, which means a theoretical minimum latency of 150 milliseconds just for light to make the journey. Add network equipment, routing hops, and protocol overhead, and real-world latency easily exceeds 200 milliseconds. ...

When you type a URL into your browser, something invisible happens before a single byte of webpage content loads. Your computer must translate that human-readable name into a machine-readable IP address—a process that typically completes in under 100 milliseconds but involves traversing a global hierarchy of servers spanning multiple continents. The Domain Name System (DNS) is often called the “phonebook of the Internet,” but that analogy undersells its complexity. A phonebook is a static directory. DNS is a distributed database with over 1,500 root server instances worldwide, millions of domain records, and caching layers at every level—all designed to resolve billions of queries per day while maintaining consistency across a system that was architected in the 1980s. ...

In 2021, the IETF published RFC 9000, formally standardizing QUIC—a transport protocol that fundamentally rethinks how data moves across the internet. By May 2024, over 12 million IPv4 addresses were responding to QUIC handshakes, and HTTP/3 now powers roughly 36% of all websites. This wasn’t an incremental improvement. QUIC abandoned TCP entirely, building a new transport on UDP to solve problems that had accumulated over four decades of internet evolution. ...