Bandwidth isn't the bottleneck, latency is. This is the book that explains what actually happens between a click and a rendered pixel — and how to cut every unnecessary round trip.
About the book
Ilya Grigorik's argument is that most web performance problems come from too many round trips, not too little throughput — a 5x bandwidth increase barely moves the needle where a 5x latency cut transforms the experience. Every request pays for DNS resolution, a TCP handshake, and TLS negotiation before a single byte of content arrives, and each step adds latency the browser can't hide. Understanding that protocol stack, from HTTP/2 to service workers, is what turns performance work from guesswork into engineering.
Best used for
—Diagnosing a slow page load by tracing DNS, TCP, TLS, and HTTP round trips
—Choosing between HTTP/2, HTTP/3, WebSocket, and SSE for a given workload
—Setting a performance budget and trimming the critical rendering path
“A must-read for every software developer. If you never cared about performance and speed down to the details, this book will change it.”
— Anton Antonov, Goodreads
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