Hierarchy Engineering 101: Relevant, Semantic Website Hierarchies for eCommerce

In the modern landscape of eCommerce, building a semantically-driven website hierarchy is no longer optional.

It’s becoming a competitive necessity for large-scale web projects.

Hierarchy engineering strengthens all digital marketing strategies.

It applies clear logic and structure to online platforms, making them easier—and faster—for users to navigate.

A well-designed hierarchy:

• Amplifies organic visibility.

• Improves the user journey.

• Enhances site architecture.

• Strengthens conversion potential.

It lays the groundwork that connects business operations, user psychology, and algorithms (search engine, LLMs and others) into one coherent system.

This guide will walk you step-by-step through hierarchy engineering—starting with foundational planning, moving through identity development, semantic clustering, crawl optimization, URL structuring, and finally, quantifying expansion.

You'll learn how to create not just a better website, but a scalable digital asset—capable of outperforming competitors and adapting to the changing future of search.

1. Start with Your Product Taxonomy

Begin by thoroughly examining your existing product taxonomy.

Your taxonomy forms the foundation of your website’s structure. It defines how products relate to each other within your site's ecosystem. It must be logical, intuitive, and grounded in real-world data—not assumptions or competitors.

At its core, a taxonomy organizes products or content into structured, hierarchical categories. 

But it doesn’t stop there.

Taxonomies are closely tied to ontologies. Where taxonomies organize, ontologies define relationships and rules, enabling more precise semantic connections.

This relationship is best illustrated by:

• Hypernyms

  (broad categories that represent general concepts) and

• Hyponyms

  (specific subcategories or instances that fall under the broader category).

For example, "Clothing" is a hypernym, while "T-shirt" is a hyponym of clothing. Similarly, "Vehicle" is a hypernym, and "Electric Scooter" would be a hyponym under that.

Understanding hypernyms and hyponyms helps search engines better parse your website because it clarifies how broader themes connect to specific topics. Hypernyms set the general theme, while hyponyms allow you to drill deeper into specialization—giving crawlers and users a map of how categories and products are grouped.

Understanding these relationships makes it easier for search engines to parse, index, and semantically interpret your content.

When you use well-structured taxonomies, ontologies, hypernyms, and hyponyms, you aren't just labeling pages. You are teaching web crawlers how to understand your site.

Leverage Google's established product taxonomies (available for the US and UK) whenever possible. These standards enhance relevancy, semantic coherence, and industry alignment.

Each child-level category naturally inherits semantic meaning from its parent, creating a hierarchy that compounds relevance as you move deeper into the structure.

Ultimately, a taxonomy built on real-world structures and semantic principles optimizes both user experience and search engine performance—ensuring your foundation is strong before you build anything else.

2. Find an Identity Keyword

An identity keyword serves as a simple, focused way to describe the business's niche in the online space—usually just one or a few words, set at the root (home) level of the website.

The best way to find a business’s identity keyword is straightforward: ask: "Describe in three words what it is that you sell." This approach cuts to the heart of the business, ensuring authenticity and relevance.

Once you have this input, you can explore its relevancy by analyzing search engine results—seeing how the term is currently classified, grouped, and understood by Google.

Choosing the right identity keyword is critical. It must succinctly and accurately describe what the business is selling, without ambiguity. Good examples include "country clothing online," "specialist tobacco shop," or "golf clothing."

When selecting your identity keyword, keep these points in mind:

• Never choose a keyword purely for its search volume. High-volume keywords are often too competitive and can dilute your ability to rank.

• Prioritize relevancy above everything. A highly relevant identity keyword creates a strong semantic core that guides all later decisions—from category structuring to content creation—ultimately improving both user experience and organic performance.

Once you've shortlisted your identity keyword, you can double-check it by:

• Text and Visual SERP Check:

  Directly search your keyword in Google (both text and image results). What appears tells you how Google classifies and groups this term. Remember, search results reflect Google's sorting algorithms at a snapshot in time—based on their latest cache and model updates.

• Assess Direct Competition:

  Input competitor homepages into SEO tools to see what keywords they're ranking for. Sometimes, Google will categorize a competitor differently than they intended—and spotting this early can uncover opportunities.

Checking competitors also gives you insights into how hierarchies and user journeys are structured within your niche, letting you find gaps to exploit and standards you may want to either follow or deliberately differentiate from.

3. Understand the User Journey

Understanding the user journey starts with thinking like a shopper: what path do they take from discovering a product to finally making a purchase?

It’s not just about clicking through pages; it’s about designing a site that reflects the natural way people explore and make decisions in your niche.

Take a few examples:

• In automotive, users typically search by "make, model, and year" to find the right vehicle.

• In electrical goods, shoppers often browse by "range," "series," or "room," aiming for consistency in design across their homes.

• In fashion, customers tend to shop by "style," "occasion," or "season," looking for items like "formal wear" for events or "summer clothes" for the warmer months.

Google’s "Messy Middle" research explains that real-world shopping behavior is far from linear—buyers often loop back and forth between exploration and evaluation before reaching a decision.

Your website hierarchy should be built to support this messy, non-linear behavior, allowing users to easily navigate, compare, and confidently move toward a purchase.

By studying and aligning your structure to these patterns, you can build a site that keeps users engaged longer, helps them find what they need more quickly, and improves the chances of turning visits into conversions.

4. Segment Your Categories By Product Range

Segmenting your categories begins with understanding—from both an operational and logistics perspective—how efficiently you can deliver products to your customers.

It makes strategic sense to shape your website experience around how quickly and easily you can fulfill customer needs, rather than treating all categories and products equally.

In practice, this means some categories should be weighted more heavily than others, promoting them prominently within the hierarchy while downplaying less critical segments that may be harder to fulfill or less profitable.

Prioritizing product segments that align with fast fulfillment and operational efficiency not only boosts customer satisfaction but also improves internal workflows.

Effective segmentation also demands a clear distinction between what qualifies as a true "category" versus what should function as a "filter."

To do this correctly, you must have a deep, well-documented understanding of your product range—allowing you to enforce consistent categorization, maintain a logical structure, and build a user-friendly, SEO-optimized hierarchy that is scalable for future growth.

5. Choosing 10-12 Top-Level Verticals

Choosing which categories to elevate as "verticals" is one of the most critical early steps in hierarchy engineering, because verticals must serve as strong, overarching holders for all their associated child categories, setting the primary structure of the hierarchy.

In most industries, verticals are already reasonably well-established, which means you often don't need to rebuild everything from scratch; instead, it usually makes more sense to strategically promote, demote, or slightly reframe verticals based on business fit, user behavior, and real-world relevance.

The general best practice is to define between 10 and 12 top-level verticals—a range that captures the breadth of your offering without overwhelming users or complicating site crawling for search engines.

Keeping verticals tight ensures a clean and navigable structure, enhances crawler efficiency, reinforces semantic clarity across the site, and minimizes the risk of content duplication or topical dilution.

When clustering verticals together, semantic logic must lead the way: categories placed adjacent to each other should have strong, meaningful relationships, because Google increasingly organizes information based on semantic clustering and topical relevance, not just navigational paths.

Grouping semantically similar topics amplifies your site's thematic authority, strengthens internal linking frameworks, and signals to search engines that your website has credible, in-depth expertise in its focus areas.

For larger enterprise operations or expansive marketplace environments, it’s sometimes appropriate to scale up to 18 verticals, and in rare cases as many as 24; however, exceeding this range should be done with caution, as too many verticals can dilute topical strength and hinder both user experience and crawlability.

Ultimately, selecting and clustering verticals should always prioritize semantic integrity, clear navigation, and long-term scalability, building a hierarchy that not only supports today's growth but adapts smoothly to future operational changes and search evolution.

6. Choosing a Crawl Depth

Choosing an optimal crawl depth is essential for both SEO and user experience because content should ideally be no more than 4-5 clicks away from the homepage, ensuring important pages are easily accessible without forcing users or search engines to dig too deeply through the site.

From Google's perspective, crawl budget is a finite resource: with billions of websites and trillions of individual URLs to potentially index, Google's crawlers must operate efficiently to keep their index accurate and up-to-date, meaning if your important content is buried too deep, it risks being deprioritized, crawled less frequently, or even completely overlooked.

A flatter and well-optimized crawl structure also allows crawlers to semantically parse sections of your website more effectively, meaning that by keeping important content closer to the surface and grouping related topics logically, you help Google better understand your site's topical relevance, which in turn can boost authority and visibility.

However, deciding on the ideal crawl depth is only part of the solution; it is equally important to monitor how search engine bots actually traverse your site, and this is where log file analysis and crawler tools come in.

Every time a crawler like Googlebot visits your site, it leaves a "footprint" in your server's log files—essentially a "black box" record of every request made—and by reviewing these logs (either manually or with specialized log analyzers), you can see exactly which pages are being crawled, how often they are visited, and whether critical pages are being properly prioritized.

Many SEO professionals use log analyzers to filter log data and isolate Googlebot’s visits, providing clarity on whether deeper pages are receiving enough attention.

In addition to log file analysis, proprietary bot crawlers (specialized software that simulates a search engine’s view of your site) can give you an even clearer picture of how your hierarchy unfolds in practice and whether your intended structure is discoverable.

Monitoring crawl behavior is vital to:

• Ensure important pages are crawled

  : Confirm that even deep-level content is getting visited regularly.

• Optimize crawl paths

  : Understand if bots are navigating efficiently or getting stuck in loops or dead-ends.

• Diagnose crawl inefficiencies

  : Identify duplicated, irrelevant, or deeply buried pages that may waste your crawl budget and reduce site efficiency.

Ultimately, managing crawl depth is not just about making content reachable—it is about strategically controlling how search engines perceive, prioritize, and organize your content to maximize search performance and ensure long-term SEO success.

7. Define Your Categories

Choosing a category is critical for hierarchy engineering because it defines how the structure will scale over time.

Categories are fixed, standalone concepts that an item either belongs to or doesn’t; they are immutable once assigned and mutually exclusive from other categories.

While categories can be promoted or demoted later depending on business needs, it’s best practice to define a stable "end state" early and expand by adding child categories rather than altering the core structure.

A true category must embody a complete concept—for example, "skinny jeans" fits logically under "jeans," but "skinny" alone cannot be extended across unrelated products like "skinny shirts."

Filters, on the other hand, should never exist at the root level. Root pages should represent foundational identities or product ranges, while filters—such as attributes like color or size—exist as refinements within a category, not standalone points.

Maintaining a clear separation between categories and filters preserves semantic clarity, improves usability, and strengthens SEO by ensuring both users and search engines can easily follow the site's logical flow.

8. Define Your Filter Groups

Defining filter groups is equally critical to building a strong hierarchy, although it operates under a very different set of principles compared to defining categories, because unlike categories, filters are designed to be flexible, adaptable, and capable of assuming multiple identities across various contexts.

For example, a filter attribute like "black" within the "colour" group can apply across many different products within the hierarchy—such as black jeans, black shirts, and black socks—allowing users to efficiently narrow down their choices based on specific needs or preferences, while enabling the site structure to dynamically accommodate diverse user intents across a wide range of product types.

To do this effectively, it is vital to plan all potential attribute groups in advance, taking care to use terminology that mirrors how customers naturally search and describe products, because consistency in filter naming not only enhances user experience but also prevents fragmentation of search signals and maximizes the semantic coherence of the website.

Moreover, it is possible to quantify the value that well-structured filters bring by calculating the incremental search opportunities they generate and incorporating these projections into your site's Total Addressable Market (TAM) planning, because capturing long-tail search queries that categories alone might miss can transform otherwise broad navigational pathways into highly targeted discovery routes, benefitting both users and search engines alike.

9. Defining URL Structures

URLs have been a fundamental part of SEO strategy since its inception, and their structure remains a critical piece of the puzzle, because short, simple, human-readable URLs benefit both web crawlers and users by improving usability, crawlability, shareability, and long-term brand recognition.

Clean URLs create a compounded positive effect over time, making it easier for users to trust and navigate your site, while making it easier for search engines to consistently crawl and index your pages.

Following Google's best practices will help you build this structure correctly from the beginning, so remember to:

• Use lowercase letters.

• Use hyphens (-) to separate words for clarity.

• Opt for static URLs over parameters where possible.

• Create a logical URL hierarchy that mirrors your actual site structure.

Plurals vs. Singulars

When defining URLs, it is generally advisable to use plural forms for categories, because research consistently shows that pluralized terms—such as "spoons" instead of "spoon"—are more aligned with commercial search intent and better suited for scalability.

Although debates exist within the SEO community (and some exceptions apply based on specific niches), using plural terms early can reduce the risk of disruptive URL migrations later on, helping to future-proof the hierarchy against technical debt.

Flat vs. Nested Hierarchies

Choosing between a flat or nested URL structure largely depends on your CMS and operational needs, because while nested hierarchies add semantic depth and naturally guide users deeper into topic clusters—making them ideal for platforms like Magento 2, OpenCart, and WordPress—flat structures are sometimes better suited for systems like Shopify, which limits the number of available parent type URLs.

Flat hierarchies tend to enable faster crawling, simpler maintenance, and more predictable SEO performance, and they can also make site management easier by reducing the need for continual restructuring every time a new intermediate category is introduced.

Ultimately, your URL strategy must respect the technical limits of your platform while aligning with SEO best practices—never force a deeply nested structure onto a system not built to support it, because doing so will almost always lead to maintenance headaches and crawlability issues down the line.

10. Plan Your Menu Layout

Your menu layout plays a critical role in shaping the user's shopping journey, acting as both the front window display and the lobby experience of your online store, meaning that it must reflect how shoppers naturally browse and move through their buying process, in alignment with the user journey mapping discussed earlier.

Some platforms, such as Shopify and WordPress, offer the flexibility to create custom menus, while others like Magento 2 and OpenCart usually default to following the site's category hierarchy but still allow adjustments through plugins or custom coding if necessary.

Ideally, you should avoid relying too heavily on custom links within the menu structure, because if category structures change, these links can easily break, leading users to frustrating 404 error pages, which not only damages user experience but can also significantly harm SEO performance.

Structuring the menu correctly is crucial for user experience (UX), conversion rate optimization (CRO), and overall purchasing potential, and a well-planned menu can further enhance the shopping journey by strategically introducing "states" within the navigation—such as promoting seasonal categories, highlighting bestsellers, or even surfacing filterable shopping options directly within the main menu when it suits common shopper behavior.

Ultimately, your menu should not just provide a way to navigate the site but should serve as an active guide that steers users deeper into their purchasing journey, helping to increase engagement, improve satisfaction, and ultimately drive higher conversion rates across the entire experience.

11. Plan Your Schema and Group Variants

Implementing schema markup effectively is critical for enhancing search visibility because schema provides search engines with clear signals about how your categories, products, and other elements fit into the overall taxonomy and ontology of your website, reinforcing semantic relationships and improving topical relevance across your hierarchy.

Since a notable portion of Google's search results page is powered by structured data—injecting information directly from schema fields—properly implementing schema can significantly boost your chances of appearing in rich results, featured snippets, and other enhanced listings, which supports your broader SEO efforts while building additional brand trust and visibility with users.

One especially important area is grouping product variants correctly, such as different colors, sizes, or styles, using structured data to help Google better understand the relationships between products and serve the most relevant versions to users in search results; following

ensures that your products are eligible for richer organic exposure and free merchant listings.

Using properties like

hasVariant

helps clearly group product variations and signals to Google the semantic relationship between different versions of a product, improving both discoverability and structured data integrity.

As large language models (LLMs) continue to advance, embedding extensive meta and product information through schema will likely become even more important, despite ongoing debates around how LLMs process structured data, because structured data—rooted in Sir Tim Berners-Lee’s original vision for the Semantic Web—remains fundamental for making content machine-readable, interconnected, and semantically powerful for the evolving future of search.

12. Quantify Your Expansion

Quantifying expansion is one of the most effective ways to demonstrate the true value of a hierarchy campaign because by measuring potential market reach early, businesses can pinpoint where to optimize and build a measurable, data-driven strategy for capturing new opportunities.

Expansion planning ensures that your website’s architecture remains aligned with real-world user demand and operational realities, avoiding the pitfalls of reactive or intuition-based structuring.

Quantification also allows for powerful segmentation, helping businesses identify high-value areas of the hierarchy, where fulfillment is strongest, and where logistics might either support or hinder growth.

This intersection of business operations and SEO hierarchy engineering is where scalable value is created, linking backend capabilities to frontend user experience and search performance.

We apply traditional business frameworks like Total Addressable Market (TAM) and Serviceable Addressable Market (SAM) to guide this process—with TAM referring to total market demand and SAM focusing on what the business can realistically serve based on its constraints.

Using these models ensures targeting and resourcing are based on real commercial potential rather than assumption, giving every structural decision a clear strategic and financial basis.

Beyond TAM and SAM, additional models such as Share of Market (SOM) projections, competitor market share analysis, and Opportunity Gap assessments can further refine targeting by uncovering immediate opportunities and longer-term growth paths.

Combining these frameworks ensures that the hierarchy you build today reflects real market needs while staying flexible enough to evolve with future changes—blending hierarchy engineering seamlessly with broader strategic planning.

13. Map Keywords to Hierarchy

Once your hierarchy is clearly defined and structured for both users and search engines, the next step is mapping keywords to the hierarchy—a manual but crucial process that moves your project from strategic planning into tactical execution.

Everything done beforehand builds the foundation, ensuring that keyword research is time well spent, because keyword mapping only delivers value when layered onto a strong, logical hierarchy.

With the structure finalized, you can begin keyword research and filtering, treating this phase as one of the final refinements that ensures every part of the hierarchy—from root categories down to subcategories and filters—is tightly aligned with user search intent and semantic relevance.

For maximum insight and effectiveness, keyword volumes should ideally be quantified across each core structural level:

• Root (Index)

• Vertical

• Levels (Subcategories)

• Filters

Breaking keyword data down in this way not only sharpens SEO strategy but also creates valuable business intelligence for product development, merchandising, and content planning, turning keyword mapping into a strategic bridge between user behavior, search demand, and wider operational priorities.

Bonus: 14. Expanding Offering & New Verticals

Always design with future growth in mind, because strategically building flexibility into your hierarchy prepares your site structure for new verticals and expanded offerings that may emerge over time, while regularly revisiting and adjusting your hierarchy ensures your site stays agile, adaptable, and ready for continued success.

Having early conversations with clients about long-term expansion is crucial, even months after a campaign begins, because with the right foresight, you can design the initial hierarchy to "park" certain categories for future development, making it far easier to grow the site naturally when the opportunity arises.

This proactive approach empowers businesses to gather real-world market data, validate new ideas, and seamlessly integrate new categories without major restructuring, while deeper future searches and expansions can be easily supported by adding additional filterable attributes, enhancing both user navigation and SEO reach without disrupting the core framework.

Ultimately, by mastering hierarchy engineering, you're not simply building a static website; you're crafting a dynamic, scalable digital asset designed to evolve fluidly alongside market shifts, technological innovations, and changing user expectations.

Conclusion

Hierarchy engineering is the art and science of building a website that mirrors human behavior, real-world market demands, and modern technological best practices, because great website architecture isn't just about stacking categories—it's about crafting a semantically rich, operationally scalable, and strategically expandable framework that can stand the test of time.

Throughout this guide, we've emphasized that successful hierarchy design comes from aligning multiple components: taxonomy, identity keywords, user journeys, crawl depth, URL structures, categories, filters, and schema—all tied together by quantifying expansion potential and mapping keywords carefully to the structure.

When all of these elements are executed thoughtfully, you aren't just creating a website; you're building a living, breathing digital asset that is discoverable, adaptable, efficient, and highly =competitive, capable of evolving alongside algorithms, user expectations, and emerging technologies.

By mastering hierarchy engineering, you position yourself not only to win today’s SEO battles but also to future-proof your digital presence for the semantic web, the ongoing rise of large language models (LLMs), and the next generation of intelligent search ecosystems.