E-commerce Site Architecture: Building for Scale

What Google Uses to Understand a Store

From the same guidance:

• Links show importance. Google can use “the number of links it needs to follow to reach a page and the number of links to a page to infer the relative importance of a page”.
• Every product needs a link path. “If category pages don’t include direct links to all products in a category, Googlebot might not find all of your products by crawling alone”, and Googlebot “generally doesn’t try to submit searches into a search box”.
• Links must be real links: use <a href> tags, not JavaScript events on other elements.
• Promote what matters: link best sellers from the home page and other content to signal their importance.

Where full linking isn’t possible, a sitemap or Merchant Center feed helps Google find the rest.

Category Hierarchy

• Mirror how shoppers choose: department, type, then the attribute that splits large groups (for example, men’s, shoes, running).
• Link down every level: menu to categories, category to subcategories, subcategory to all its products, with pagination where lists are long.
• Keep important pages close to the home page in clicks, through the menu, category links and featured links.
• Split categories when they become hard to browse, not at a fixed product count, and merge categories too small to help.
• Use merchandising collections (“Summer Essentials”) alongside the attribute hierarchy, as linked pages with their own purpose rather than near-copies of a category.

Category page content is covered in category page optimization.

URL Structure

Google’s ecommerce URL guidance is about avoiding crawl and duplication problems:

• One URL per piece of content: minimize alternative URLs that return the same page; “Google cannot determine” that /product/black-t-shirt and /product?sku=1234 are the same “by looking at the URL alone.”
• Consistent case if your server treats upper and lower case alike.
• No fragments for different content: “Google does not use fragment identifiers in indexing.”
• Descriptive words in paths: “The words in URLs may help Google better understand the page.”
• Standard parameters: ?key=value, no repeated parameters.
• A unique URL for each paginated page.

Google adds that on an ecommerce platform “you can most likely skip this section”, since platforms handle much of it. Hierarchical paths (/mens/shoes/oxford/) and flat ones (/products/oxford/) both work; choose one and keep it stable, because changing URL patterns later means redirects for every page.

Filters, Sorting and Variants

• Filters and sort orders generate URLs fast. For those that don’t need to rank, Google’s first suggestion is robots.txt disallow; a noindex doesn’t save crawling because the page still has to be fetched. See faceted navigation SEO.
• Variants (color, size) either share one product URL with options on the page, or get their own URLs where shoppers search for them; in the second case, keep each variant indexable with its own canonical and group them with variant markup, rather than combining noindex with a canonical.
• Tracking parameters shouldn’t appear in internal links.

Navigation

• Main menu: top-level categories and the pages that matter most, as crawlable HTML links.
• Mega menus: fine if the links are in the HTML; check the rendered page.
• Footer: policies, help, key categories; not a list of everything.
• Breadcrumbs: on category and product pages, with BreadcrumbList markup; Google shows breadcrumbs in desktop results. See BreadcrumbList schema.
• Related products: crawlable links chosen for shoppers.

Internal linking principles are in internal linking strategy.

Planning for Growth

Document the rules before the catalog outgrows them:

Then test the rules against expected growth: more categories, more filters, new markets. Discontinued product handling is in out-of-stock and discontinued products, and international structure in international SEO fundamentals.

Monitoring a Growing Catalog

• Crawl stats in Search Console: the share of requests going to filter, sort or parameter URLs.
• Page indexing report: products not indexed, duplicates, unexpected exclusions.
• Crawls of the site to find orphan products, deep pages and redirect chains; see crawl analysis tools.
• Server logs for what Googlebot actually requests; see log file analysis.

Platform-specific constraints are covered in e-commerce technical SEO.

Two decisions are costly to change later, the URL pattern and the variant model, because changing either means redirects across the catalog; settle both before the catalog grows.