Site Architecture

Site Architecture & Internal Linking

Production-grade website architecture framework covering URL hierarchy design, internal linking strategy, navigation optimization, silo structure, and crawl equity management. Handles architecture audits, new site planning, and restructuring existing sites.

Table of Contents

• Operating Modes
• URL Structure Design
• Navigation Architecture
• Silo Structure and Topic Clusters
• Internal Linking Strategy
• Crawl Equity Management
• Architecture Audit Framework
• Restructuring Playbook
• Architecture Patterns by Site Type
• Common Mistakes
• Output Artifacts
• Related Skills

Clarify First

Before generating the architecture, confirm these inputs. If any is unknown or vague, ASK — do not assume:

• [ ] Operating mode — audit current, plan new, internal-linking optimization, or URL restructuring — determines the artifact produced
• [ ] Site type — SaaS, e-commerce, blog/content, local, docs, or marketplace — selects the URL pattern and architecture template
• [ ] Core topics / silos — the 3-7 topic clusters the site covers — drives the hub-and-spoke and internal-linking plan
• [ ] Current URLs / crawl data — sitemap or URL export — required for audits and redirect mapping

Stop rule: ask only the 2-3 that most change the output. If the user says "just draft it," proceed and list your assumptions at the top of the artifact.

Operating Modes

Mode 1: Audit Current Architecture

Existing site needs structural assessment. Analyze depth distribution, orphan pages, link equity flow, and navigation effectiveness.

Mode 2: Plan New Architecture

Building from scratch or full redesign. Map business goals to site sections, design URL hierarchy, plan navigation, and define content silos.

Mode 3: Internal Linking Optimization

Structure is fine but link equity flow needs improvement. Identify hub pages, map spoke content, fix orphans, and optimize anchor text.

Mode 4: URL Restructuring

Changing URLs on an existing site. Plan the new structure, build redirect maps, and manage the migration.

URL Structure Design

Depth Guidelines

| Depth | Example | Use When | SEO Impact |

|-------|---------|----------|------------|

| 1 level (flat) | /cold-email-tips | Blog posts, standalone pages | Best crawl equity per page |

| 2 levels | /email-marketing/cold-email-tips | Category is a rankable page itself | Good, category page accumulates authority |

| 3 levels | /solutions/marketing/email-automation | Product families, nested services | Acceptable if each level has content |

| 4+ levels | /a/b/c/d/page | Never | Diluted equity, poor UX, crawl issues |

Decision rule: If the intermediate directory URL (/email-marketing/) will NOT be a real page with its own content and ranking target, do not create the directory. Flat is better than empty hierarchy.

URL Construction Rules

| Rule | Good | Bad | Why |

|------|------|-----|-----|

| Use hyphens | /seo-audit | /seo_audit | Underscores are not word separators for Google |

| Be descriptive | /pricing | /pricing-page | Redundant suffixes add nothing |

| Keep short | /guides/technical-seo | /guides/technical-seo-audit-checklist-complete-guide | Readability matters |

| Include keyword | /guides/seo-audit | /guides/article?id=4827 | Descriptive URLs rank better |

| Be consistent with trailing slashes | Pick one: /about or /about/ | Mix of both | Inconsistency creates duplicate content |

| Use lowercase | /about-us | /About-Us | Case sensitivity varies by server |

URL Patterns by Site Type

| Site Type | Pattern | Example |

|-----------|---------|---------|

| SaaS | /features/[feature], /solutions/[use-case], /integrations/[partner] | /features/analytics, /solutions/marketing, /integrations/slack |

| E-commerce | /[category]/[subcategory]/[product] | /mens/shoes/running-shoes-pro |

| Blog/Content | /blog/[slug] or /blog/[category]/[slug] | /blog/seo-audit-guide |

| Local business | /[service]/[location] | /plumbing/austin-tx |

| Documentation | /docs/[section]/[page] | /docs/api/authentication |

| Marketplace | /[category]/[listing] | /designers/john-smith |

Navigation Architecture

Navigation Zones

Every site has 6 navigation zones. Each serves a different purpose and carries different SEO weight.

| Zone | Items | SEO Weight | Design Rule |

|------|-------|------------|-------------|

| Primary nav | 5-8 items max | High (sitewide equity) | Only pages you want to rank for. Never "Resources" without a landing page. |

| Secondary nav | 3-7 per section | Medium | Sub-navigation within a section/silo |

| Breadcrumbs | Dynamic | High (upward equity) | Every non-homepage page. Each segment must be a real link. |

| Footer nav | 8-15 items max | Low-Medium | Key pages only. Not a dumping ground for every page. |

| Contextual (in-content) | 3-5 per page | Highest | Most powerful signal. Natural editorial links within body content. |

| Sidebar | 5-10 items | Low-Medium | Related content, category listing |

Primary Navigation Design

Rules:

• 5-8 items maximum. Cognitive overload starts at 9+ items.
• Every nav item links to a page you actively want to rank.
• Dropdown menus are fine, but the parent item must be a clickable, crawlable link (not just a hover trigger).
• Do not put utility pages (Contact, Privacy, Terms) in primary nav -- they belong in the footer.
• Mobile nav must expose the same structure as desktop nav (no hidden critical pages).

Breadcrumb Implementation

Add breadcrumbs to every non-homepage page. They serve three functions:

• UX: Show users their location in the hierarchy
• SEO: Create sitewide upward internal links to hub/category pages
• Rich results: Enable BreadcrumbList schema for SERP breadcrumbs

Format: Home > Category > Subcategory > Current Page

Rules:

• Every breadcrumb segment must be a real, crawlable link
• Never use breadcrumbs as styled text without links
• Add BreadcrumbList schema markup alongside visible breadcrumbs
• Breadcrumb hierarchy should match URL hierarchy

Silo Structure and Topic Clusters

Hub-and-Spoke Model

A silo is a self-contained cluster of content about one topic, where all pages link to each other and to a central hub page.

                    ┌──────────────────┐
                    │     HUB PAGE     │
                    │   /seo/          │
                    │   (Pillar content)│
                    └────────┬─────────┘
            ┌────────────────┼────────────────┐
       ┌────┴────┐      ┌───┴────┐      ┌────┴────┐
       │ SPOKE 1 │      │ SPOKE 2│      │ SPOKE 3 │
       │technical│      │on-page │      │  link   │
       │  seo    │      │  seo   │      │building │
       └────┬────┘      └───┬────┘      └────┬────┘
            │                │                │
       Cross-links     Cross-links      Cross-links
       between         between          between
       related         related          related
       spokes          spokes           spokes

Building Topic Clusters

Step 1: Identify 3-7 core topics for your site (these become your silos)

Step 2: For each topic, create one pillar page (the hub) that covers the topic broadly

Step 3: Create spoke content for each major sub-question or sub-topic

Step 4: Implement linking:

• Hub links DOWN to every spoke
• Every spoke links UP to the hub (with keyword-rich anchor text)
• Spokes link ACROSS to related spokes within the same silo
• Cross-silo links are fine when contextually genuine

Step 5: Build the content before building the links. Links to non-existent content are useless.

Silo Depth Guidelines

| Silo Size | Recommended Depth | Structure |

|-----------|------------------|-----------|

| 3-5 spokes | Flat | Hub + spokes, all at same level |

| 6-15 spokes | Shallow nested | Hub > Sub-hubs > Spokes |

| 16-50 spokes | Two-level | Hub > Category sub-hubs > Individual spokes |

| 50+ spokes | Paginated | Hub > Category sub-hubs > Paginated spoke listings |

Internal Linking Strategy

Link Equity Power Stack

Not all internal links carry equal weight. From most to least powerful:

| Rank | Link Type | Weight | When to Use |

|------|-----------|--------|-------------|

| 1 | In-content contextual link | Highest | Natural editorial links within body copy |

| 2 | Hub page link | High | Pillar page linking to all its spokes |

| 3 | Navigation link | Medium | Sitewide, consistent, but diluted by ubiquity |

| 4 | Breadcrumb link | Medium | Upward equity flow, consistent |

| 5 | Footer link | Low | Sitewide, Google discounts these |

| 6 | Sidebar link | Low | Often not in main content flow |

Anchor Text Strategy

| Type | Example | Usage | Signal Strength |

|------|---------|-------|-----------------|

| Partial match | "effective cold email strategies" | Primary approach (60-70% of links) | Strong |

| Exact match | "cold email templates" | Use sparingly (10-15% of links) | Strong but risky if overused |

| Branded | "our email guide" | Natural variation (10-15%) | Moderate |

| Descriptive | "this comprehensive guide" | Natural variation (5-10%) | Weak but natural |

| Generic | "click here", "learn more" | Avoid (< 5%) | None -- wasted signal |

| Naked URL | https://example.com/guide | Never for internal links | None |

Orphan Page Detection and Resolution

An orphan page is indexed in Google but has zero inbound internal links. It is invisible to the site's link graph.

Detection method:

• Export all indexed URLs (GSC Coverage or site: query)
• Export all internal link targets (crawl tool or link extraction)
• Pages in set A but not set B are orphans

Resolution actions:

| Orphan Type | Action |

|-------------|--------|

| Valuable content, belongs in a silo | Add contextual links from 3+ related pages |

| Old content, still relevant | Link from hub page and 1-2 spokes |

| Outdated content, no value | Redirect to relevant page or noindex |

| Utility page (shouldn't be indexed) | Add noindex |

Internal Linking Audit Checklist

| Check | Pass Criteria |

|-------|---------------|

| Every content page has 3-5 outbound internal links | No page links only to itself or navigation |

| Every target page has 3+ inbound internal links | No orphans in the indexed set |

| Hub pages link to all their spokes | Complete coverage |

| Anchor text is descriptive and varied | No > 30% exact match for any keyword |

| No broken internal links | 0 broken links |

| Link depth from homepage < 4 clicks | 95%+ of pages within 3 clicks |

Crawl Equity Management

Homepage Equity Distribution

The homepage is your highest-equity page. Use it wisely.

| Homepage Link Target | Priority |

|---------------------|----------|

| Hub/pillar pages (top of each silo) | Highest -- link from homepage content area |

| Key product/service pages | High -- link from homepage or primary nav |

| Top-performing content | Medium -- link if contextually relevant |

| Utility pages (contact, about) | Low -- footer links only |

| Blog index | Medium -- primary or secondary nav |

Crawl Budget Allocation

| Page Category | % of Crawl Budget | Optimization |

|--------------|-------------------|--------------|

| Money pages (product, pricing, features) | 20-30% | Internal link from homepage + nav |

| Pillar content (hub pages) | 20-30% | Extensive internal linking |

| Spoke content (blog, guides) | 30-40% | Linked from hubs + contextual |

| Utility pages (about, contact, legal) | 5-10% | Footer links only, minimal crawl |

| Tag/archive/pagination | < 5% | Noindex if thin, limit crawling |

Architecture Audit Framework

Audit Scorecard

| Dimension | Weight | Check |

|-----------|--------|-------|

| Crawl depth | 20% | 95%+ pages within 3 clicks of homepage |

| Orphan pages | 20% | 0 orphan pages in indexed set |

| URL cleanliness | 15% | Clean, descriptive, consistent URLs |

| Navigation completeness | 15% | All key pages accessible via primary/secondary nav |

| Internal link coverage | 15% | Every page has 3+ inbound internal links |

| Silo coherence | 10% | Topic clusters are well-defined with clear hub-spoke relationships |

| Breadcrumb implementation | 5% | Present on all non-homepage pages with schema |

Red Flag Indicators

| Signal | Severity | Action |

|--------|----------|--------|

| Pages > 3 clicks from homepage | High | Create shortcuts via nav or hub page links |

| Hub page has no content (just links) | High | Add pillar content to all hub pages |

| Generic anchor text dominant (> 30%) | Medium | Rewrite anchor text to be descriptive |

| No breadcrumbs on deep pages | Medium | Implement breadcrumbs with BreadcrumbList schema |

| Sitemap includes noindex pages | Medium | Filter sitemap to only indexable pages |

| Primary nav links to utility pages | Low | Move Contact/Privacy to footer |

| Footer contains 50+ links | Low | Reduce to 8-15 key pages |

Restructuring Playbook

When to Restructure

| Signal | Restructure? | Alternative |

|--------|-------------|-------------|

| Complete URL overhaul needed | Yes | -- |

| Adding 3 new sections | Partial -- new sections only | -- |

| Fixing orphan pages | No | Add internal links, no URL changes needed |

| Improving nav | No | Update navigation, keep URLs |

| Moving to new CMS | Yes (usually) | Keep URL structure if CMS supports it |

Restructuring Steps

• Crawl current site -- Export all URLs, internal links, and rankings
• Map current to new -- Create 1:1 URL redirect mapping
• Build redirect rules -- 301 redirects for every changed URL
• Chain existing redirects -- Update old redirects to point to final destination
• Update internal links -- Point to new URLs (do not rely on redirects for internal links)
• Update sitemap -- Reflect new URL structure
• Monitor for 60 days -- Watch for crawl errors, ranking changes, traffic impact

Architecture Patterns by Site Type

SaaS Website

/                           Homepage
├── /features/              Features hub
│   ├── /features/analytics Analytics feature
│   └── /features/reporting Reporting feature
├── /solutions/             Solutions hub (by use case)
│   ├── /solutions/marketing Marketing use case
│   └── /solutions/sales    Sales use case
├── /integrations/          Integrations hub
│   ├── /integrations/slack Slack integration
│   └── /integrations/salesforce Salesforce integration
├── /pricing                Pricing page
├── /blog/                  Blog index
│   ├── /blog/seo-guide     Blog post
│   └── /blog/growth-tips   Blog post
├── /docs/                  Documentation
└── /about                  About page

E-commerce Site

/                           Homepage
├── /[category]/            Category page (with content)
│   ├── /[category]/[subcategory]/ Subcategory (with content)
│   │   └── /[category]/[subcategory]/[product] Product page
│   └── /[category]/[product]      Product (if no subcategory)
├── /brands/                Brand hub
│   └── /brands/[brand]     Brand page
├── /blog/                  Content hub
└── /sale/                  Promotions hub

Content/Media Site

/                           Homepage
├── /[topic]/               Topic hub (pillar content)
│   ├── /[topic]/[subtopic] Subtopic article
│   └── /[topic]/[guide]    In-depth guide
├── /authors/               Author hub
│   └── /authors/[name]     Author page
├── /tools/                 Free tools hub
│   └── /tools/[tool]       Individual tool
└── /newsletter             Newsletter signup

Common Mistakes

| Mistake | Why It Hurts | Fix |

|---------|-------------|-----|

| Orphan pages | No equity flows in, Google deprioritizes | Add contextual internal links from related content |

| URL changes without redirects | Lost link equity and broken backlinks | Always 301 redirect old URLs |

| Deep nesting (4+ levels) | Diluted crawl equity, confusing UX | Flatten structure |

| Empty category pages | Thin pages do not rank | Add pillar content to all category/hub pages |

| Homepage linking to nothing | Wastes highest-equity page | Link from home to all hub pages |

| Footer with 100+ links | Dilutes equity across too many targets | Limit footer to 8-15 key pages |

| Navigation not matching user mental model | Users leave, engagement drops | Run card-sort testing with real users |

| Dynamic parameter URLs | Creates duplicate content | Canonicalize or block with robots.txt |

| Sitewide sidebar links to every post | Diluted equity, adds noise | Remove or limit to "popular" posts |

Output Artifacts

| Artifact | Format | Description |

|----------|--------|-------------|

| Architecture Audit Scorecard | Weighted score table | Per-dimension scores with red flag indicators |

| Site Tree Diagram | Text-based hierarchy | Visual URL structure with annotations |

| URL Specification Table | Table | URL pattern, title template, parent page, schema type per section |

| Internal Linking Plan | Hub-spoke map | Topic cluster map with anchor text guidelines and orphan fix list |

| Redirect Map | Before/after URL table | 1:1 mapping for URL restructuring with 301 implementation |

| Navigation Spec | Zone-by-zone design | Primary, secondary, breadcrumb, footer, and contextual nav plans |

Related Skills

• seo-audit -- For comprehensive SEO audits where architecture is one of several problem areas. Use seo-audit for the full picture, site-architecture for deep structural work.
• schema-markup -- For adding BreadcrumbList and other structured data after architecture decisions are finalized.
• programmatic-seo -- For hub-and-spoke structures at scale when generating hundreds of template-based pages.
• content-creator -- For creating the pillar content that hub pages need to rank effectively.

Troubleshooting

| Problem | Likely Cause | Fix |

|---------|-------------|-----|

| Orphan pages appearing in Google index | Pages exist in sitemap or have external links but no internal links pointing to them | Add contextual internal links from 3+ related pages; update hub pages to include them |

| Crawl depth exceeds 4+ clicks for key pages | Flat navigation missing or hub pages not linking to spokes | Create shortcut links via primary nav, hub page content blocks, or featured sections |

| Category/hub pages ranking poorly | Hub pages have no substantive content — just link lists | Add 800+ words of pillar content to every hub page; they must rank on their own merit |

| Redirect chains after site migration | Old redirects not updated to point to final destination; chains accumulate over multiple migrations | Audit all existing redirects; collapse chains so every redirect points directly to the final URL |

| Internal links using generic anchor text | "Click here" and "learn more" anchor text dominating internal links | Rewrite anchors to be descriptive with partial-match keywords; aim for 60-70% partial match |

| New sections not getting crawled | No internal links from existing high-authority pages to new section | Add contextual links from homepage and related hub pages; submit new section sitemap |

Success Criteria

• Crawl depth: 95%+ of indexable pages reachable within 3 clicks from homepage
• Zero orphan pages: No indexed pages without at least 3 inbound internal links
• URL cleanliness: 100% of URLs follow the established pattern — lowercase, hyphenated, descriptive, consistent trailing slash policy
• Navigation coverage: All key revenue and pillar pages accessible via primary or secondary navigation
• Internal link density: Every content page has 3-5 outbound contextual internal links with descriptive anchor text
• Silo coherence: Each topic cluster has a defined hub page with bidirectional links to all spokes
• Breadcrumb coverage: BreadcrumbList schema present on 100% of non-homepage pages

Scope & Limitations

In scope:

• URL hierarchy design and restructuring
• Navigation architecture (primary, secondary, breadcrumb, footer, contextual, sidebar)
• Silo structure and topic cluster planning
• Internal linking strategy and optimization
• Crawl equity analysis and optimization
• Architecture audits with scored reports
• URL migration planning with redirect mapping

Out of scope:

• Content creation for hub pages (use Content Production)
• Schema markup implementation (use Schema Markup)
• Technical SEO beyond architecture (use SEO Audit)
• Visual design or UX design of navigation
• CMS development or template coding
• External link building

Known limitations:

• Crawl equity distribution is estimated — Google does not publish exact PageRank flow data
• Architecture changes on large sites (10K+ pages) require careful phased migration to avoid traffic loss
• Navigation testing (card sorts, tree tests) requires user research tools and participants
• Cross-silo linking recommendations are qualitative — no deterministic formula exists for optimal cross-linking density

Scripts

# Analyze sitemap for depth and structure issues
python scripts/sitemap_analyzer.py --file sitemap.xml --json

# Check URLs for redirect chains and patterns
python scripts/redirect_checker.py --file urls.txt --json

# Map internal link structure from a sitemap
python scripts/link_mapper.py --sitemap sitemap.xml --json