Page 10 - Web Performance

WebSocket-based GraphQL Subscriptions bring bidirectional communication that most realtime use cases don't even need. Server-Sent Events, as a GraphQL Subscriptions alternative, offer a simpler, HTTP-native path for unidirectional updates, without a custom protocol, a custom reconnect mechanism, or extra infrastructure.

A line in exception.log barely reveals which customer was affected or which order got stuck in checkout. Sentry error tracking captures exceptions with full context, automatically groups recurring errors, and turns anonymous stack traces into traceable incidents with a clear priority.

A large JavaScript bundle costs more than download time, it blocks the main thread while parsing and compiling. With dynamic import(), vendor chunk splitting, and targeted lazy loading of heavy below-the-fold widgets, initial bundle size drops noticeably without losing functionality, even in server-rendered Hyva stores built on Alpine.js.

The Fetch API is more than a replacement for XMLHttpRequest. Anyone who masters timeouts, retry logic, streaming responses, authentication and cache strategies writes HTTP communication that stays reliable and maintainable in real applications, without external libraries.

A classic PHP-FPM request automatically frees all its memory at the end, while a Swoole or RoadRunner worker lives on through thousands of requests within the same process. That exact difference turns static state, forgotten closures and growing caches into a real memory leak that slowly eats up available memory over hours of operation.

Classic server-side rendering forces the server to fully render the entire component tree before a single byte can be sent to the browser. If any component depends on a slow database query or an external API call, the whole response waits as long as the slowest component takes, even if nine out of ten sections of the page have long been ready. React 18 solves this with real streaming SSR: renderToPipeableStream sends HTML in multiple chunks as they become ready, instead of waiting for the entire page. Combined with Suspense boundaries, you can precisely control which sections ship immediately and which ones follow later, with measurable improvements in Time to First Byte and perceived load time.

Assembling product pages in the browser with JavaScript risks empty Google previews, delayed indexing, and wasted crawl budget. This article compares server-side rendering, client-side rendering, and hybrid approaches purely from an SEO angle, and explains why Magento's server-rendered PHTML with Hyvä Theme holds a structural advantage over heavy single-page applications, especially for large catalogs with a limited rendering budget.

Scroll event listeners for visibility checks are outdated and expensive. The Intersection Observer delivers viewport notifications without blocking the main thread, without layout thrashing, and with configurable thresholds, the modern solution for lazy loading, scroll animations and infinite scroll.

Before a service runs in production with multiple replicas in Kubernetes or Docker Swarm, it is worth testing locally with deploy.replicas in Docker Compose. This way, port conflicts, shared volumes and load balancing behavior can be uncovered on the development machine, instead of noticing them only after a production rollout.

Modern Magento stores built with Hyvä Theme and Alpine.js render large parts of their content in the browser, yet Google crawls, renders, and indexes that content in separate, time-shifted phases. This article explains how the Web Rendering Service works, which mistakes make client-side rendered pages invisible, and how URL Inspection and clean hydration timing ensure Googlebot truly sees everything.