If you're still running a Luma-based theme on your Magento 2 store in 2026, you're leaving significant performance on the table. The Hyvä theme has matured into the de-facto frontend standard for Magento developers who care about speed, maintainability, and Core Web Vitals. This guide explains exactly why, with numbers to back it up. The Problem with Luma Luma shipped with Magento 2.0 in 2015. It was designed for an era before Lighthouse scores, INP metrics, or the performance bar Google sets today. Under the hood, Luma relies on: RequireJS for module loading — hundreds of individual JS requests (or a slow bundled blob) KnockoutJS for UI components — a heavy runtime that initialises on every page jQuery and dozens of jQuery plugins CSS compiled from deep LESS inheritance chains The result? A typical Luma homepage ships with 400–600 KB of JavaScript that must parse and execute before anything interactive works. On a fast connection and a desktop Chrome, this is tolerable.…