Sylius is a mature open-source e-commerce framework built on Symfony, organized as a monorepo of decoupled PHP bundles and domain components. In production it powers multi-channel, multi-currency, multi-locale storefronts with product catalogs, carts and checkout, order management, payments via Payum, taxes, shipping, promotions and coupons, inventory, customer accounts, and an admin panel. It exposes a JSON:API via API Platform for headless commerce, a Twig/Stimulus storefront, an admin interface, and CLI commands for installation, user management, and maintenance. The domain logic lives primarily in the Sylius Component and Bundle layers, with UI and API layers acting as adapters over shared services.