Page 2 - Web Performance

The Speculation Rules API lets a site tell the browser which pages the user is likely to visit next, so they can be loaded or even fully rendered ahead of time, making the actual navigation feel instant. Unlike classic prefetching, it can prepare entire pages including JavaScript execution in the background.

Most developers only use DevTools as a console tab. Yet Chrome DevTools hides techniques that cut debugging time in half, surface performance problems in seconds and shine a light through the entire network stack of a JavaScript project, without writing a single line of extra code.

Schema migration in IndexedDB differs fundamentally from server side database migrations: there is no migration tool, no SQL DDL commands and no central place to run scripts, only the onupgradeneeded event, a single version number, and the developer's responsibility to change object stores and indexes step by step, robustly and backward compatibly.

Lighthouse CI measures performance in a controlled, repeatable way directly inside the pipeline, preventing slow deployments from ever going live. This article explains the difference from Real User Monitoring, walks through a complete lighthouserc configuration with budget assertions, covers historical trend tracking, and shows why testing only the homepage creates a dangerous false sense of security for Magento stores.

Every new TCP and TLS connection costs several network round trips before the first useful byte reaches the client, and naive implementations pay that setup cost again on every single request. HTTP Keep-Alive, connection pools between PHP-FPM and backend services, and modern HTTP/2 and HTTP/3 multiplexing eliminate exactly this overhead. This article shows how Nginx, Redis, MySQL, and Guzzle clients deliberately reuse connections.

Browsers constantly make decisions about which resource to request next while loading a page. The fetchpriority attribute lets you override those heuristics on purpose and tell the browser exactly which images, scripts, or links are actually critical for the first paint.

HTTP/3 replaces TCP with the new transport protocol QUIC, solving a problem HTTP/2 never fully fixed despite multiplexing. Understanding how head of line blocking, 0-RTT handshakes, and connection migration actually work technically lets you realistically judge what the new protocol really does for Magento stores and their mobile visitors.

Server-side rendering is supposed to deliver fast first visibility, yet in large SPA/SSR hybrid applications the hydration step that follows often eats up exactly the advantage server-side rendering just created. The browser has to walk the entire component tree again, attach event handlers, and reconstruct internal state before the page becomes truly interactive. Partial hydration and the fundamentally different concept of resumability are two answers to the same problem, with very different consequences for architecture and framework choice.

Alpine.js bundle size looks insignificantly small at first glance, but once plugins, the CSP build variant and several component libraries add up, the exact composition decides noticeable differences in load time and time to interactive. Knowing the kilobyte numbers and the CSP tradeoffs leads to deliberate rather than accidental decisions when assembling a bundle.

A single Redis instance is enough for most Magento stores for a long time, but under very heavy traffic it eventually hits clear limits, both in available memory and in the maximum throughput a single process can sustain. Redis Cluster solves this by horizontally distributing data across multiple nodes, but it brings its own tuning questions that simply do not exist with a single instance. This article covers the sharding strategy and hash slot distribution, shows how to pick the right memory eviction policy, and explains how to reliably detect unevenly distributed load on individual shards.