SEO Interview Questions

SEO (Search Engine Optimization) is the practice of optimizing websites to rank higher in search engine results, driving free organic traffic. It matters because organic search accounts for ~53% of all website traffic, and the first 5 results on Google get ~70% of all clicks. Unlike paid ads, organic traffic is sustainable and compounds over time.

Three steps: (1) Crawling — Googlebot follows links across the web to discover pages. (2) Indexing — Google analyzes the content and stores it in a massive database. (3) Ranking — When someone searches, Google scores indexed pages against 200+ ranking factors and returns the most relevant results.

On-Page SEO (content quality, HTML tags, keywords, internal links), Technical SEO (site speed, crawlability, mobile-friendliness, schema), and Off-Page SEO (backlinks, domain authority, brand signals). A strong SEO strategy addresses all three.

Experience, Expertise, Authoritativeness, Trustworthiness. It's the quality framework Google's human raters use to evaluate search results. While not a direct ranking factor, it influences how Google's algorithms assess content quality. It's especially important for YMYL (Your Money or Your Life) topics like health, finance, and legal content.

White hat follows Google's guidelines — quality content, natural link building, technical optimization. Black hat violates guidelines for quick gains — keyword stuffing, cloaking, link schemes, hidden text. Gray hat is in between — not explicitly banned but questionable (e.g., aggressive guest posting for links). Black hat risks manual penalties or algorithmic devaluation.

Informational (learn: "what is SEO"), Navigational (find: "Google Search Console login"), Transactional (buy: "buy Ahrefs subscription"), Commercial investigation (compare: "Semrush vs Ahrefs"). Matching content to search intent is critical for ranking.

In order of importance: (1) Title tag — unique, 50-60 chars, keyword at front. (2) H1 tag — one per page, matches intent. (3) Content quality — comprehensive, original, readable. (4) Internal links — descriptive anchors, hub-and-spoke. (5) Meta description — compelling CTR driver. (6) URL structure — clean, keyword-rich. (7) Image alt text — descriptive, keyword where natural.

(1) Brainstorm seed keywords from the topic. (2) Use tools (Keyword Planner, Ahrefs, Semrush) to find search volume and difficulty. (3) Analyze search intent — Google the keyword and see what type of content ranks. (4) Choose keywords where your content can realistically compete — start with long-tail keywords (lower competition). (5) Map one primary keyword per page plus 3-5 secondary keywords.

Keyword cannibalization happens when multiple pages target the same keyword, confusing Google about which to rank. Fix it by: (1) Consolidating — merge pages into one comprehensive page with a 301 redirect. (2) Differentiating — retarget one page for a different, related keyword. (3) Canonicalizing — use canonical tags to indicate the preferred version.

There's no magic number — match the intent. Informational guides that rank well average 1,500-2,500 words. But a recipe might rank with 500 words, while a comprehensive guide might need 5,000+. The goal isn't word count — it's covering the topic as thoroughly as the searcher needs, no more, no less. Check what length the current top results use as a benchmark.

Internal links: (1) Help Google discover and crawl new pages. (2) Pass link equity (ranking power) from strong pages to weaker ones. (3) Signal topic relationships and site structure. (4) Reduce bounce rate by guiding users to related content. Use descriptive anchor text, link contextually within content, and follow a hub-and-spoke model for topic clusters.

Core Web Vitals are Google's page experience metrics: LCP (loading — ≤2.5s), INP (interactivity — ≤200ms), CLS (visual stability — ≤0.1). They became a ranking factor in 2021. They measure real-user experience, and pages that fail CWV may rank lower than equivalent pages that pass.

Crawling is when Googlebot visits a URL and reads its content. Indexing is when Google processes that content and stores it in its database. A page can be crawled but not indexed (if it has noindex, thin content, or is a duplicate). Only indexed pages can appear in search results.

301 (Permanent) — tells Google the page has permanently moved. Link equity transfers to the new URL. Google will eventually index only the new URL. 302 (Temporary) — tells Google the move is temporary. Link equity stays with the original URL. Google keeps the original URL indexed. Use 301 for permanent URL changes, 302 for A/B tests or temporary maintenance pages.

A canonical tag (<link rel="canonical">) tells Google which version of a page is the "official" one when duplicates exist. Use it for: HTTP/HTTPS duplicates, www/non-www, URL parameter variations, syndicated content, and paginated series. It consolidates ranking signals to the preferred URL.

(1) Optimize images — WebP format, compression, lazy loading. (2) Minimize JavaScript — defer non-critical JS, code-split, remove unused code. (3) Use a CDN — serve assets from edge locations. (4) Enable caching — set long cache-control headers for static assets. (5) Preload critical resources — fonts, CSS, hero images. (6) Reduce server response time — upgrade hosting, use HTTP/2+.

Structured data (JSON-LD format) is code added to pages that helps Google understand the content type. It can trigger rich results — enhanced SERP features like FAQ dropdowns, star ratings, recipe cards, and breadcrumbs. Common types: Article, FAQPage, HowTo, Product, BreadcrumbList, LocalBusiness.

Since 2023, Google uses the mobile version of every page as the primary version for indexing and ranking — even for desktop searches. This means your mobile site must have the same content, structured data, and meta tags as your desktop site. Sites without a mobile-friendly experience will rank lower.

A high-quality backlink: (1) Comes from a high-authority domain (e.g., NYT, university sites). (2) Is topically relevant to your content. (3) Uses descriptive anchor text. (4) Is editorially earned (not paid or exchanged). (5) Is placed within body content (not footer/sidebar). (6) Comes from a page that has its own backlinks.

Dofollow links (default) pass link equity and act as endorsements. Nofollow links (rel="nofollow") tell Google not to pass equity. Google now treats nofollow as a "hint" rather than a directive. Other link attributes: rel="sponsored" (paid links) and rel="ugc" (user-generated content like comments).

(1) Create linkable assets — original research, infographics, tools, calculators. (2) Guest posting on authoritative sites in your niche. (3) Broken link building — find broken links on other sites, offer your content as a replacement. (4) Digital PR — create newsworthy content/studies, pitch to journalists. (5) Unlinked brand mentions — find sites that mention your brand without linking, ask them to add a link.

Domain Authority (DA) is a third-party metric by Moz (0-100) predicting ranking potential. It's based primarily on the quality and quantity of backlinks. Note: DA is NOT a Google metric — Google doesn't use it. Ahrefs has a similar metric called Domain Rating (DR). These tools reverse-engineer ranking potential but are approximations, not direct ranking factors.

Two types: (1) Manual action — a human reviewer flags your site (visible in GSC). Fix the violation, then submit a reconsideration request. (2) Algorithmic penalty — an algorithm update devalues your rankings (no notification). Diagnose by correlating traffic drops with known updates. Recovery: remove/disavow toxic links, improve content quality, fix the specific issue flagged. Recovery can take weeks to months.

Primary: Organic traffic (GSC/GA4), keyword rankings, organic conversions. Technical: Index coverage, Core Web Vitals, crawl errors. Content: Click-through rate (CTR), average position, pages per session. Authority: Referring domains, new backlinks. Track these weekly/monthly to spot trends and measure ROI of SEO efforts.

(1) Track organic conversions in GA4 (sign-ups, purchases, leads). (2) Calculate cost-per-acquisition from organic vs. paid. (3) Estimate traffic value — multiply organic traffic by equivalent CPC from Google Ads. (4) Track revenue attribution from organic landing pages. (5) Compare month-over-month and year-over-year growth to show trend. SEO ROI increases over time as content compounds.

Google Search Console (GSC) shows how Google sees your site — search queries, impressions, clicks, CTR, index coverage, Core Web Vitals, crawl errors. Google Analytics (GA4) shows what users do on your site — traffic sources, pageviews, session duration, conversions, user behavior. Use GSC for SEO diagnostics and GA4 for user behavior and conversion tracking.

(1) Technical foundation — HTTPS, mobile-friendly, fast, sitemap, robots.txt. (2) Keyword research — find long-tail keywords with low competition. (3) Content plan — create 10-20 cornerstone articles targeting those keywords. (4) On-page optimization — proper titles, metas, headings, internal links. (5) Topic clusters — build hub-and-spoke content architecture. (6) Link building — start with digital PR and guest posting. (7) Measure & iterate — use GSC to track what's working after 3-6 months.

(1) Check indexing in GSC — are pages actually indexed? (2) Check for technical issues — noindex tags, robots.txt blocking, JavaScript rendering problems. (3) Evaluate keyword targeting — are you targeting keywords that are too competitive? Switch to long-tail. (4) Assess content quality — is it genuinely better than what currently ranks? (5) Check backlinks — a new site with zero links struggles to rank. Start building. (6) Look for cannibalization. 6 months is still early for SEO — ensure the foundation is right.

(1) Map all old URLs to new URLs in a spreadsheet. (2) Implement 301 redirects for every URL change. (3) Update internal links to point to new URLs. (4) Update sitemap, canonical tags, and robots.txt. (5) Submit new sitemap to GSC. (6) Monitor GSC crawl errors, index coverage, and traffic daily for 4-6 weeks. (7) Keep old redirects live for at least 1 year. A botched migration is the #1 cause of catastrophic traffic loss.

AI is changing SEO in several ways: (1) AI Overviews in Google can answer queries directly, reducing clicks to websites (zero-click searches). (2) Content quality bar rises — AI-generated commodity content won't rank; you need original insights, data, and expertise. (3) E-E-A-T becomes more important — first-hand experience differentiates from AI-written content. (4) New traffic sources — optimizing for AI chatbot citations is emerging. (5) Long-tail wins — specific, nuanced queries still drive clicks because AI can't always provide depth.

SEO (Search Engine Optimization) focuses on organic (free) rankings. SEM (Search Engine Marketing) includes both SEO and paid search (PPC/Google Ads). In practice, most people use "SEM" to mean paid search specifically. SEO is a long-term investment (3-6+ months to see results); PPC delivers immediate traffic but stops when you stop paying. The best strategy uses both.

(1) Google Search Central Blog — official announcements. (2) Google Search Status Dashboard — algorithm update tracking. (3) Twitter/X — follow John Mueller, Danny Sullivan, Barry Schwartz. (4) Industry sites — Search Engine Journal, Ahrefs Blog, Moz Blog. (5) Google Search Console — watch your own data for algorithm impact. (6) Test your own sites — experimentation is the best teacher.