Answer

**Liquid and Shopify themes** | Topic | Key points | Source | |-------|------------|--------| | **Global objects** | Every Liquid file automatically has access to objects such as `cart`, `customer`, `product`, and store settings. Knowing which objects can be combined (e.g., `customer` + `cart` for personalization) is essential for building rich themes. | [1] | | **theme.liquid essentials** | Shopify only requires two Liquid objects in `theme.liquid`: `{{ content_for_header }}` and `{{ content_for_layout }}`. Missing or mis‑placed objects silently break the admin, app scripts, or checkout. | [6] | | **Linting vs. runtime** | The Liquid code linted by tools may differ from what Shopify actually executes, so developers should test against the live environment. | [7] | | **Performance patterns** | Common slow patterns include using `{% capture %}` inside loops, excessive image tags, and complex filters. Optimizing these can reduce render time by 40‑60%. | [8] | | **New block & partial tags** | Shopify now supports `{% block %}` and `{% partial %}` tags, enabling modular page composition and reusability in themes. | [5] | | **Future direction** | Liquid is expanding beyond theme templating: PHP/Python support is GA, and new features target agentic commerce (e.g., product metafields for LLMs). | [4] | These points cover the most relevant aspects of Liquid as it relates to theme development and performance.