Technical SEO covers the infrastructure work that lets search engines access, crawl, interpret, and index your website without friction. It's separate from content or links—you're optimizing the machine-readable foundation. Core components include crawl efficiency (robots.txt, XML sitemaps, crawl budget management for large sites), indexing controls (canonical tags, noindex directives, hreflang for multilingual sites), site architecture (logical URL structure, internal linking hierarchy, pagination handling), and page speed (Core Web Vitals, server response time, image compression, caching). Mobile responsiveness isn't optional anymore—Google's been mobile-first since 2019, so responsive design and mobile usability fall squarely in technical SEO territory. Security and structured data matter too. HTTPS is a ranking signal and a trust factor. Structured data (schema markup) helps Google display rich snippets—reviews, FAQs, breadcrumbs, local business info—which can significantly lift click-through rates even if rankings stay flat. You'll also handle error resolution: 404s, 301 redirect chains, orphaned pages, duplicate content caused by URL parameters or session IDs, and server errors that block Googlebot. Log file analysis becomes critical on sites with 10,000+ pages—you want to see where Google wastes crawl budget and fix it. JavaScript rendering is increasingly relevant. If your site relies on React or Vue, you need to confirm Google renders it properly, either through server-side rendering, pre-rendering, or dynamic rendering fallbacks. Google's better at JS than five years ago, but it's not flawless. At Ottawa SEO, we treat technical SEO as the foundation. A site with perfect content and strong backlinks still underperforms if it's slow, hard to crawl, or throws indexing errors. We'll run Screaming Frog audits, check Search Console for coverage issues, test Core Web Vitals in real Chrome data, and prioritize fixes by impact—usually speed and mobile first, then crawl issues, then advanced schema. Technical work isn't glamorous, but it's where you unlock rankings that content alone can't deliver.