Juan RojasSenior ShopifyEngineer.

1theme/2├── blocks/             # reusable theme blocks3├── sections/           # schema-driven, merchant-editable4├── snippets/           # pure render partials5├── templates/*.json    # composed in the theme editor6├── assets/             # ES modules, loaded per section7└── config/settings_schema.json8 9extensions/10├── checkout-ui/        # Checkout UI Extension11└── volume-discount/    # Shopify Function12 13.github/workflows/14└── theme-ci.yml        # theme check + deploy

1{%- liquid2  assign featured = section.settings.collection3  assign limit = section.settings.products_to_show4-%}5 6<ul class="product-grid" role="list">7  {%- for product in featured.products limit: limit -%}8    {%- assign eager = false -%}9    {%- if forloop.index <= 4 -%}10      {%- assign eager = true -%}11    {%- endif -%}12    <li>{% render 'card-product', product: product, eager: eager %}</li>13  {%- endfor -%}14</ul>15 16{% schema %}17{18  "name": "Featured collection",19  "settings": [20    { "type": "collection", "id": "collection", "label": "Collection" },21    { "type": "range", "id": "products_to_show",22      "min": 2, "max": 12, "default": 8, "label": "Products" }23  ],24  "presets": [{ "name": "Featured collection" }]25}26{% endschema %}

1import {useLoaderData} from '@remix-run/react';2import type {LoaderFunctionArgs} from '@shopify/remix-oxygen';3 4export async function loader({params, context}: LoaderFunctionArgs) {5  const {product} = await context.storefront.query(PRODUCT_QUERY, {6    variables: {handle: params.handle!},7    cache: context.storefront.CacheLong(),8  });9 10  if (!product) throw new Response('Product not found', {status: 404});11  return {product};12}13 14export default function ProductRoute() {15  const {product} = useLoaderData<typeof loader>();16  return <ProductDetails product={product} />;17}

1'use client';2import {useTransition} from 'react';3 4type Variant = {id: string; availableForSale: boolean};5type QuickAddProps = {6  variants: Variant[];7  onAdd: (variantId: string) => Promise<void>;8};9 10export function QuickAdd({variants, onAdd}: QuickAddProps) {11  const [isPending, startTransition] = useTransition();12  const variant = variants.find((v) => v.availableForSale);13 14  return (15    <button16      type="button"17      disabled={!variant || isPending}18      onClick={() => variant && startTransition(() => onAdd(variant.id))}19    >20      {isPending ? 'Adding…' : variant ? 'Add to cart' : 'Sold out'}21    </button>22  );23}

1// @ts-check2import {DiscountApplicationStrategy} from '../generated/api';3 4const NO_DISCOUNT = {5  discounts: [],6  discountApplicationStrategy: DiscountApplicationStrategy.First,7};8 9/** @param {import('../generated/api').RunInput} input */10export function run(input) {11  const quantity = input.cart.lines12    .reduce((total, line) => total + line.quantity, 0);13 14  if (quantity < 3) return NO_DISCOUNT;15 16  return {17    discountApplicationStrategy: DiscountApplicationStrategy.First,18    discounts: [{19      message: '10% off 3+ items',20      targets: [{orderSubtotal: {excludedVariantIds: []}}],21      value: {percentage: {value: '10.0'}},22    }],23  };24}

1import {2  reactExtension,3  Banner,4  useSubtotalAmount,5} from '@shopify/ui-extensions-react/checkout';6 7const FREE_SHIPPING_AT = 75;8 9export default reactExtension(10  'purchase.checkout.block.render',11  () => <FreeShippingNudge />,12);13 14function FreeShippingNudge() {15  const {amount, currencyCode} = useSubtotalAmount();16  const remaining = Math.max(FREE_SHIPPING_AT - amount, 0);17 18  return remaining > 0 ? (19    <Banner status="info">20      Add {remaining.toFixed(2)} {currencyCode} for free shipping.21    </Banner>22  ) : (23    <Banner status="success">Free shipping unlocked.</Banner>24  );25}

1{%- comment -%} LCP image: preload + high priority {%- endcomment -%}2{{3  product.featured_media4  | image_url: width: 16005  | image_tag:6    widths: '400, 800, 1200, 1600',7    sizes: '(min-width: 990px) 50vw, 100vw',8    loading: 'eager',9    fetchpriority: 'high',10    preload: true11}}12 13<script type="module">14  // Non-critical widgets wait until the main thread is idle15  const idle = window.requestIdleCallback ?? ((cb) => setTimeout(cb, 1));16  idle(() => import('{{ 'reviews-widget.js' | asset_url }}'));17</script>

1import {createHmac, timingSafeEqual} from 'node:crypto';2import {erp, subscriptions, analytics} from './clients';3 4/** Verify a Shopify webhook before trusting its payload. */5export function isValidWebhook(rawBody: string, hmac: string | null, secret: string) {6  if (!hmac) return false;7  const digest = createHmac('sha256', secret).update(rawBody, 'utf8').digest('base64');8  const a = Buffer.from(digest);9  const b = Buffer.from(hmac);10  return a.length === b.length && timingSafeEqual(a, b);11}12 13export async function onOrderCreated(order: ShopifyOrder) {14  // One failing system never blocks the others15  await Promise.allSettled([16    erp.upsertOrder(order),17    subscriptions.syncCustomer(order.customer),18    analytics.track('order_created', {id: order.id}),19  ]);20}