100 Technical SEO interview questions and answers

A comprehensive set of technical SEO interview questions and answers, designed for candidates with some experience (junior to mid-level) as well as advanced professionals. The list covers crawling, indexing, rendering, site architecture, JavaScript SEO, structured data, Core Web Vitals, log analysis, redirects, canonicalization, international SEO, and more.

I’ve organized them into logical categories and provided detailed, practical answers.

Crawling & Indexing

1. What is the difference between crawling and indexing?
Answer: Crawling is the discovery process where search engine bots (like Googlebot) follow links to find new or updated pages. Indexing is the storage and organization of those pages into the search engine’s database. A page must be crawled before it can be indexed, but crawling does not guarantee indexing.

2. How does Googlebot decide which pages to crawl and how often?
Answer: Googlebot uses a crawl budget – a combination of crawl rate limit (how many requests per second) and crawl demand (how important/updated the page is). Factors: PageRank, URL freshness, site size, server health, and internal linking. High-authority pages get crawled more frequently.

3. What is a crawl budget and why does it matter?
Answer: Crawl budget is the number of URLs Googlebot will crawl on a site within a given time. It matters for large sites (millions of URLs). Wasting crawl budget on low-value pages (faceted navigation, infinite spaces, duplicate pages) can prevent important pages from being crawled/indexed.

4. How can you optimize crawl budget?
Answer:

Use robots.txt to block worthless paths (e.g., internal search results).
Use noindex on low-value pages (but allow crawl).
Fix broken links and server errors (5xx, 4xx).
Consolidate duplicate content with canonical tags.
Update XML sitemaps with only important URLs.
Avoid infinite spaces (e.g., calendar pagination).

5. What is the difference between a 200, 301, 302, 404, and 410 status code?
Answer:

200 OK – page loaded normally.
301 Moved Permanently – permanent redirect, passes link equity.
302 Found – temporary redirect, may not pass equity.
404 Not Found – page missing, could come back.
410 Gone – page permanently removed, faster de-indexing than 404.

6. What is a noindex tag? How do you implement it?
Answer: It tells search engines not to index a page. Implement via <meta name="robots" content="noindex"> in HTML <head> or via X-Robots-Tag HTTP header. Note: if a page is blocked by robots.txt, Google may never see the noindex directive.

7. Can a page be indexed if it’s blocked by robots.txt?
Answer: Yes, it’s possible. Google may still discover the URL from external links and decide to index it without crawling the content (using only the anchor text and URL). To prevent indexing, use noindex and allow crawling, or password-protect the page.

8. What is the purpose of an XML sitemap? How often should it be updated?
Answer: An XML sitemap lists URLs you want search engines to crawl, especially pages that might not be discovered through internal links. It should be updated whenever new pages are added or existing ones are removed (real-time for dynamic sites, daily for most sites). Large sites need a sitemap index file.

9. How do you submit a sitemap to Google?
Answer: Through Google Search Console (GSC): go to Sitemaps, enter the sitemap URL (e.g., /sitemap.xml) and click submit. Alternatively, place the sitemap location in robots.txt using Sitemap: https://example.com/sitemap.xml.

10. What is the lastmod tag in a sitemap? Is it important?
Answer: lastmod indicates the last modification date of a URL. Google uses it as a hint, but it is not a strong signal. However, if the value is inaccurate, Google may ignore it. It’s most useful for regularly updated content.

11. What is a robots.txt file? Give an example of a directive.
Answer: robots.txt tells crawlers which paths they are not allowed to crawl. Example:

text

User-agent: Googlebot  
Disallow: /internal-search/  
Disallow: /temp/  
Allow: /public/  
Sitemap: https://example.com/sitemap.xml

12. How do you test a robots.txt file?
Answer: Use Google Search Console’s “robots.txt Tester” tool. It shows which directives are enabled and allows you to test specific URLs to see if they are blocked.

13. What is a “soft 404” error? Why is it bad?
Answer: A soft 404 is when a server returns a 200 OK status but the content is a “page not found” message (or very thin content). It wastes crawl budget and confuses Google. Fix by returning a proper 404 or 410 status code.

14. How do you check if a specific URL is indexed by Google?
Answer: Use the site: operator (site:example.com/url-path) or the URL Inspection Tool in Google Search Console. The latter shows the indexed version, any issues, and allows you to request re-indexing.

15. What is the difference between “Crawled – currently not indexed” and “Discovered – currently not indexed” in GSC?
Answer:

Crawled – currently not indexed: Googlebot visited the URL but chose not to index it (usually due to low quality, duplicate content, or canonical issues).
Discovered – currently not indexed: Google knows the URL exists (e.g., from sitemap or links) but hasn’t crawled it yet (often due to crawl budget limits).

Rendering & JavaScript SEO

16. How does Google handle JavaScript-heavy websites?
Answer: Googlebot uses a two-wave indexing system. First wave: HTML-only crawl (without executing JS). Second wave: after rendering (may take days or weeks). Critical content should be available in the initial HTML using server-side rendering (SSR) or dynamic rendering.

17. What is the difference between client-side rendering (CSR), server-side rendering (SSR), and static rendering?
Answer:

CSR: Browser downloads a minimal HTML + JS, then JS builds the page. Problematic for SEO if content is not visible in raw HTML.
SSR: Server generates full HTML for each request. Good for SEO but higher server load.
Static rendering: Pre-builds HTML files at build time (for non-dynamic content). Best for speed and SEO.

18. What is dynamic rendering? When would you use it?
Answer: Dynamic rendering serves a fully rendered HTML version to crawlers (based on user-agent detection) while serving the normal client-side experience to users. Use for large JS-heavy sites where full SSR is not feasible. Google approves this method.

19. How can you test if Google can see your JavaScript-generated content?
Answer: Use the URL Inspection Tool in GSC, then click “View Tested Page” and see the rendered HTML. Also use the “Fetch as Google” (legacy) or mobile-friendly test. If the rendered version lacks key content, you have a JS SEO issue.

20. What is rel="canonical" in a JavaScript-driven single-page application (SPA)?
Answer: Even in SPAs, the canonical tag must be present in the initial HTML (not generated by JS after load), because Google’s first wave may not execute JS. If the canonical is only added by JS, it may be missed.

21. How do you handle routing in an SPA for SEO?
Answer: Use the History API (pushState) to create unique, crawlable URLs for each view (avoid hash fragments #). Ensure each URL returns a distinct HTML response (or prerendered version). Use a sitemap with all routes.

22. What is the difference between a noindex directive and a robots.txt disallow for JavaScript-generated pages?
Answer: robots.txt disallow prevents crawling but Google may still index the URL if discovered elsewhere. noindex prevents indexing, but Google must be able to crawl the page to see the tag. For JS pages, ensure the noindex is in the initial HTML, not injected later.

23. What is a “hashbang” URL (#!/about)? Are they still relevant?
Answer: Hashbangs were a workaround for AJAX crawling (Google’s deprecated “escaped_fragment” spec). They are no longer recommended. Use the History API instead.

24. How does lazy loading impact SEO?
Answer: Lazy loading defers loading images or content until they are needed (e.g., when scrolling). If used improperly (e.g., lazy loading critical text or links), Googlebot may never see that content. Use native loading="lazy" attributes for images, not custom JS that hides content.

25. What tools can you use to debug JavaScript SEO issues?
Answer:

Google Search Console URL Inspection Tool (rendered version)
curl with user-agent (to see raw HTML)
Chrome DevTools with “Disable JavaScript” to simulate first wave
Fetch as Google (legacy)
Rendering tools like Puppeteer or Headless Chrome

Site Architecture & Internal Linking

26. What is a flat site architecture? Why is it good for SEO?
Answer: A flat architecture means any page is reachable within 3–4 clicks from the homepage. It distributes link equity more evenly, improves crawl efficiency, and helps search engines discover pages faster.

27. What is “orphan page”? How do you find and fix it?
Answer: An orphan page has no internal links pointing to it. Google may still discover it via external links or sitemap, but it won’t receive link equity. Find using crawling tools (Screaming Frog’s “orphan pages” report). Fix by adding contextual internal links from relevant pages.

28. How do you optimize internal link anchor text?
Answer: Use descriptive, natural anchor text that tells both users and Google what the linked page is about. Avoid generic “click here” or exact-match keyword repetition (over-optimization). Diversify with branded, partial-match, and generic anchors.

29. What is the maximum number of internal links per page you should have?
Answer: No hard technical limit, but Google’s John Mueller has suggested a few hundred per page is fine. For usability, prioritize important links and avoid excessive footer/sidebar links that dilute equity.

30. What is a “breadcrumb” and how does it help SEO?
Answer: Breadcrumbs are a secondary navigation trail (e.g., Home > Category > Product). They improve user experience and allow rich snippets in SERPs when marked up with BreadcrumbList schema.

31. What is the difference between a content silo and a topic cluster?
Answer: A content silo groups pages tightly with internal links within a single category, minimizing cross-linking to other categories. A topic cluster uses a pillar page and supporting articles that interlink, allowing some cross-linking but maintaining thematic relevance.

32. How would you structure URLs for a large ecommerce site with categories and subcategories?
Answer: Example: example.com/men/shoes/running/ – keep URL depth reasonable (max 3-4 levels). Use hyphens, not underscores. Avoid parameters for main content. Include relevant keywords.

33. What is “pagination” and how should you handle it for SEO?
Answer: Pagination splits long lists across multiple pages. Google no longer uses rel="prev/next". Best practices: use a “View All” page if feasible; otherwise, ensure each paginated page has unique content (e.g., product order variations) or canonical to the first page if content is identical.

34. How do you deal with faceted navigation (filter URLs) to prevent duplicate content?
Answer: Options:

Use robots.txt to block crawling of filter parameters.
Use noindex on filter pages.
Use canonical tags pointing to the main category page.
Use URL parameters tool in GSC to tell Google how to handle them.
Use rel="nofollow" on filter links (less effective).

35. What is a “cornerstone content” strategy?
Answer: Cornerstone content is your most important, comprehensive pages that you want to rank the highest. They should receive the most internal links from related blog posts and sit high in the site architecture (close to homepage).

Redirects & Canonicalization

36. What is the difference between a 301 and a 302 redirect in terms of SEO?
Answer: A 301 passes nearly all link equity (PageRank) to the target URL. A 302 is intended for temporary moves and may not pass equity. Google now treats 302s more like 301s if they persist, but best practice: use 301 for permanent moves, 302 for temporary.

37. What is a redirect chain and why is it bad?
Answer: A redirect chain is a series of two or more redirects (e.g., A → B → C → D). It dilutes link equity, increases page load time, and wastes crawl budget. Ideally, redirect directly from original to final URL (A → D).

38. What is a redirect loop? How do you detect it?
Answer: A redirect loop occurs when a URL redirects to another that eventually redirects back to the original (A → B → A). It makes the page inaccessible. Detect using crawlers (Screaming Frog) or browser dev tools.

39. When would you use a 302 redirect instead of a 301?
Answer: For temporary scenarios: A/B testing, seasonal promotions, site maintenance, or country-specific temporary landing pages.

40. What is the difference between a canonical tag and a 301 redirect?
Answer: A 301 redirect sends users and bots to a different URL. A canonical tag tells search engines which version should be considered the master, but users still see the original URL. Use canonical for duplicate content you want to keep accessible (e.g., print versions); use 301 when you want to consolidate permanently.

41. Can you use a canonical tag across domains?
Answer: Yes, rel="canonical" can point to a URL on a different domain (cross-domain canonical). This is useful for syndicated content. However, Google treats it as a strong hint, not a directive.

42. How do you handle migrating a site from HTTP to HTTPS regarding redirects?
Answer: Use 301 redirects from each HTTP URL to its HTTPS equivalent. Update internal links, sitemap, canonical tags, and hreflang to HTTPS. Test thoroughly. Also submit new HTTPS sitemap via GSC.

43. What is a “non-canonical page” – and can it rank?
Answer: A non-canonical page is one that has a canonical tag pointing to another URL. It may still rank for some queries, but Google generally indexes the canonical version. Non-canonical pages might get very little organic traffic.

44. How do you find broken redirects on a large website?
Answer: Use a crawler like Screaming Frog (list of redirect chains), DeepCrawl, or Sitebulb. Set the crawler to follow redirects and output any that end in 4xx/5xx or form loops.

45. What is a “canonical conflict”? Give an example.
Answer: A canonical conflict occurs when signals disagree. Example: Page A canonical to Page B, but Page B canonical to Page A (mutual). Or: sitemap includes Page A, but Page A’s canonical points to Page C. Google may ignore both.

Structured Data & Schema Markup

46. What is schema markup? Why is it important for technical SEO?
Answer: Schema markup (using Schema.org vocabulary) helps search engines understand the meaning of your content. Technically, it’s JSON-LD, Microdata, or RDFa. It enables rich results (reviews, events, FAQs) which improve CTR, but it is not a ranking factor.

47. What format does Google recommend for structured data? Why?
Answer: JSON-LD (JavaScript Object Notation for Linked Data). It’s easiest to implement and maintain because it lives in a <script> tag and doesn’t alter the visible HTML.

48. How do you test if your structured data is valid?
Answer: Use Google’s Rich Results Test (for specific types) and the Schema Markup Validator (for syntax). Also test in Google Search Console’s “Enhancements” reports.

49. What is the difference between Product and Offer schema?
Answer: Product describes the item itself (name, brand, image, SKU). Offer describes the sale (price, currency, availability, condition). They are often nested: product contains an offer.

50. What is BreadcrumbList schema and how does it affect SERPs?
Answer: BreadcrumbList marks up navigation trails. When valid, Google may show breadcrumb paths in search snippets (e.g., Home > Category > Product), improving visibility and CTR.

51. Can you use multiple schema types on one page?
Answer: Yes. Use an @graph in JSON-LD to list multiple types (e.g., Product and Review and Organization). Ensure they are properly nested or referenced.

52. What is FAQ schema and what are its limitations?
Answer: FAQ schema allows you to show a list of questions and answers directly in SERPs. As of 2023, Google restricts FAQ rich results to only authoritative government, health, and certain sites – many sites no longer see them. Check Google’s latest guidelines.

53. What is LocalBusiness schema and what properties are required?
Answer: LocalBusiness schema (or a subtype like Restaurant) helps with local SEO. Required: name, address (with streetAddress, addressLocality, addressRegion, postalCode, addressCountry), and telephone.

54. How does structured data help with E-E-A-T?
Answer: Structured data like author, datePublished, organization, and sameAs can make it easier for Google to connect your content to real-world entities, supporting Expertise, Authoritativeness, and Trustworthiness.

55. What is the difference between noindex and blocking structured data with robots.txt?
Answer: If you block a page with robots.txt, Google may not crawl it, so it will never see any structured data on that page. For pages you want indexed but without rich results, use noindex or omit the structured data.

Core Web Vitals & Page Experience

56. What are Core Web Vitals?
Answer: A set of user-centric metrics that measure real-world user experience:

LCP (Largest Contentful Paint): loading performance – good if <2.5s.
INP (Interaction to Next Paint): responsiveness (replaced FID) – good if <200ms.
CLS (Cumulative Layout Shift): visual stability – good if <0.1.

57. What is the difference between FID and INP?
Answer: FID measured only the first input delay. INP measures the responsiveness of all interactions (clicks, taps, key presses) throughout the page’s lifecycle. INP became a Core Web Vital in March 2024.

58. How do you measure Core Web Vitals for a page?
Answer: Field data – Chrome User Experience Report (CrUX) via PageSpeed Insights, Google Search Console (Core Web Vitals report), or web-vitals JavaScript library. Lab data – Lighthouse.

59. What are the most common causes of poor LCP and how to fix them?
Answer:

Slow server response → improve hosting, use CDN.
Large images → compress, use modern formats (WebP, AVIF).
Render-blocking resources → defer or inline critical CSS.
Client-side rendering → implement SSR.

60. How do you improve INP (responsiveness)?
Answer: Break up long JavaScript tasks (>50ms). Use requestIdleCallback or web workers. Debounce event handlers. Avoid layout thrashing. Reduce main thread work.

61. What causes CLS and how can you prevent it?
Answer: Elements that move after load – e.g., images without dimensions, dynamically inserted ads/embeds, fonts causing FOIT/FOUT. Fix by: specifying width/height for images, using CSS aspect-ratio, reserving space for ads.

62. What is the difference between lab data and field data for Core Web Vitals?
Answer: Lab data (Lighthouse) is measured in a controlled environment, good for debugging. Field data (CrUX) is based on real Chrome users, reflects actual experience. Google uses field data for ranking.

63. A page has good lab data but poor field data. Why?
Answer: Field data captures real-world variations: slower devices, poor network conditions, location of servers, and user interactions. Lab test may use fast simulation. Check for distribution of scores in CrUX.

64. What other page experience signals does Google consider?
Answer: Mobile-friendliness, HTTPS security, intrusive interstitials, safe browsing (no malware).

65. How does page speed affect crawl budget?
Answer: Slow pages reduce the number of URLs Googlebot can crawl per second. If your server is slow, Googlebot will decrease its crawl rate, potentially delaying indexing of new or updated pages.

Log File Analysis & Crawl Data

66. What are server log files and why are they valuable for SEO?
Answer: Log files record every request made to a server, including those from search engine bots. They provide ground truth about: which URLs Googlebot crawls, frequency, status codes, crawl depth, and crawl budget usage – not just what GSC shows.

67. What information can you extract from log files for SEO?
Answer: Bot user-agent, requested URL, HTTP status code, timestamp, referrer, IP address, response size, and server load. You can identify orphan pages, crawl inefficiencies, and server errors.

68. How do you differentiate Googlebot from other bots in logs?
Answer: Googlebot user-agent strings are publicly documented (e.g., Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)). Also verify by reverse DNS lookup: googlebot.com domain.

69. What is “crawl depth” in log files?
Answer: The number of clicks it took for Googlebot to reach a URL from the homepage. Deep URLs (e.g., 5+ clicks) are crawled less frequently and may be deprioritized. Logs help you see actual crawl patterns.

70. How do you find crawl budget waste using log files?
Answer: Identify URLs with:

Status 4xx/5xx (wasted requests)
noindex pages that are still being crawled
Infinite spaces (calendar parameters)
URLs that have not changed (last-modified header)
URLs blocked by robots.txt (but still requested)

71. What tools can you use to analyze log files?
Answer: Screaming Frog Log File Analyzer, ELK Stack (Elasticsearch), GoAccess, AWStats, or custom Python scripts.

72. How often should you analyze log files for an enterprise site?
Answer: Monthly or quarterly for ongoing monitoring. After major changes (site migration, redesign) – weekly.

International & Multilingual SEO

73. What is hreflang and how does it work?
Answer: hreflang is an HTML attribute (or sitemap entry) that tells Google which language or regional version of a page to serve to users, based on their language/region settings. It prevents duplicate content across international sites.

74. What are the three ways to implement hreflang?
Answer:

In the HTML <head> using <link rel="alternate" hreflang="en-us" href="...">.
In HTTP headers (for non-HTML files).
In XML sitemap (one entry per language variant).

75. How would you implement hreflang for a large ecommerce site with 10 languages?
Answer: Use a sitemap-based approach. Generate separate sitemaps per language or include xhtml:link entries. Automate via CMS or script. Avoid manual entry for thousands of pages. Also ensure each language version has self-referential hreflang.

76. What is the difference between lang HTML attribute and hreflang?
Answer: lang (e.g., <html lang="en">) tells browsers and screen readers the language of the document. hreflang tells search engines about alternate language/region versions of the page. They serve different purposes.

77. How do you handle a site that serves content by IP geolocation without URL changes?
Answer: That’s problematic for SEO because Googlebot crawls from mostly US IPs. Provide clear language selectors and use hreflang. If content changes based on IP, Google may index only one version. Use separate URLs or subdirectories (e.g., /en/, /fr/).

78. What is the “x-default” hreflang value?
Answer: x-default tells Google which page to show to users who do not match any language/region targeting. Typically, it points to a neutral page (e.g., global homepage or a language selector).

79. What are common hreflang mistakes?
Answer:

Missing return links (if page A links to B, B must link back to A).
Using hreflang without canonical tags (each language version should self-canonical).
Incorrect country/language codes (e.g., en-uk instead of en-gb).
Blocking by robots.txt.

80. How do you test hreflang implementation?
Answer: Use Google Search Console’s International Targeting report. Also use the hreflang checker tool (e.g., Merkle’s). Crawl the site with Screaming Frog and inspect alternate links.

HTTPS, Security & Migrations

81. Why is HTTPS important for SEO?
Answer: Google uses HTTPS as a lightweight ranking signal. More importantly, it secures data, prevents injection attacks, and avoids “Not Secure” browser warnings, which hurt trust and click-through rates.

82. What is a mixed content error? How does it affect SEO?
Answer: Mixed content occurs when an HTTPS page loads resources (images, scripts) over HTTP. Browsers may block or warn users. It can break functionality and reduce user trust. Fix by updating all resource URLs to HTTPS.

83. What is HSTS (HTTP Strict Transport Security)? Should you implement it?
Answer: HSTS forces browsers to always use HTTPS, preventing downgrade attacks. Implement after your HTTPS migration is stable. Add the header: Strict-Transport-Security: max-age=31536000; includeSubDomains. But be careful – it’s irreversible for the duration.

84. What is the difference between a domain migration and a platform migration?
Answer: Domain migration changes the domain name (e.g., oldsite.com → newsite.com). Platform migration keeps the same domain but changes CMS/platform (e.g., Joomla → WordPress). Both require redirect mapping and careful pre/post-launch checks.

85. List the steps for a safe site migration from an SEO perspective.
Answer:

Inventory all old URLs.
Create 301 redirect mappings (1:1 where possible).
Run migration on staging and test.
Update internal links, canonical tags, sitemaps, hreflang.
Launch during low traffic.
Monitor GSC for crawl errors, indexing, and ranking changes.
Update external links where possible (Google Business Profile, directories).

86. How long does it take for Google to re-index a migrated site?
Answer: It can take 4–8 weeks for significant ranking changes to settle. However, basic indexing of new URLs may happen within days if you submit sitemaps and have a strong backlink profile.

87. What is a “change of address” tool in Google Search Console?
Answer: For domain migrations, you can notify Google of the new domain using GSC’s Change of Address tool (under Settings). It helps Google associate the old site’s signals with the new domain.

88. What are the risks of a CDN (Content Delivery Network) for SEO?
Answer: CDNs can improve speed, but risks include:

Different IP addresses for different regions (Google crawls from US – ensure the CDN serves same content).
Incorrectly configured hreflang or canonical headers.
SSL certificate issues.
Blocking crawlers by mistake.

89. What is a “canonicalization” issue when moving from HTTP to HTTPS?
Answer: After migration, both HTTP and HTTPS versions may be accessible. Use 301 redirects from HTTP to HTTPS, also set the canonical tag on HTTPS pages to themselves, and update internal links to HTTPS.

90. How do you handle URL structure changes within the same domain?
Answer: Use 301 redirects from old to new URLs. Ensure no chain of redirects. Update internal links and sitemap. Monitor for 404 errors for at least 3 months.

Advanced & Troubleshooting

91. What is “cloaking”? Why is it prohibited?
Answer: Cloaking is serving different content to search engines than to users. It’s a black-hat technique that violates Google’s guidelines and can lead to a manual penalty or de-indexing.

92. What is “canonicalization” in the context of pagination?
Answer: Some SEOs wrongfully canonical paginated pages (e.g., page 2) to the first page. This tells Google that page 2 should not be indexed, which can cause loss of traffic to deeper content. Instead, use noindex on paginated pages if they are thin.

93. How do you debug “crawled – currently not indexed” for quality pages?
Answer: Possible causes:

Thin content even though page looks valuable.
Duplicate content (check canonical).
Crawl budget limits (site too large).
JavaScript rendering issues – check rendered HTML.
Poor internal linking (orphan page).
Solution: improve content, add internal links, use “request indexing” sparingly.

94. What is a “soft 404” and how can you detect it in logs?
Answer: A page with 200 status but “page not found” content. Detect by analyzing response body length (too small) or using machine learning on content. GSC also reports soft 404s in the Coverage report.

95. How does Googlebot handle URLs with fragments (#)?
Answer: By default, Google ignores fragment identifiers (the part after #) because they are for in-page navigation. If you need separate content, use the History API instead of fragments. Google will only crawl the fragment-less URL.

96. What is “canonical chaining” and why avoid it?
Answer: Page A canonical to B, B canonical to C. Google may follow the chain but it adds complexity. Directly canonical to the final URL.

97. How do you prioritize technical SEO fixes in a large enterprise?
Answer: Use impact vs. effort matrix:

High impact, low effort: broken canonical tags, soft 404s, redirect chains.
High impact, high effort: converting JS-heavy pages to SSR.
Low impact, low effort: obsolete sitemaps.
Also CRUD (critical, high, medium, low) based on revenue-driving pages.

98. What is “index bloat” and how do you fix it?
Answer: Index bloat is having many low-value pages indexed (e.g., faceted filters, user profiles, thin pages). It dilutes your site’s overall quality. Fix by:

Adding noindex to appropriate pages.
Using parameter handling in GSC.
Consolidating with canonical tags.

99. How do you handle SEO for a site that uses subdomains vs. subdirectories?
Answer: From a technical SEO perspective, subdirectories (domain.com/blog/) are simpler because they consolidate domain authority. Subdomains (blog.domain.com) are treated almost like separate sites, requiring separate link building. Use subdomains only for completely separate products or user-generated content.

100. You launch a site and see that none of the pages are indexed after 2 weeks. What do you check?
Answer:

robots.txt – is it blocking Googlebot?
Meta noindex tags – are they present?
Server returns 200 status?
Is the site in crawler’s view (use URL Inspection Tool)?
No manual action in GSC.
XML sitemap submitted and valid.
Internal links are crawlable (not using JavaScript only).
No password protection or firewall blocking Google.

Use these questions to prepare for technical SEO interviews at junior to advanced levels. Focus not just on definitions but on explaining how you would diagnose and fix issues in real-world scenarios. Good luck!