As a developer who's implemented SEO for multiple clients, I've learned that technical SEO matters more than content marketing promises. This guide covers the developer-focused SEO techniques that actually impact rankings: Structured data implementation (Schema.org, JSON-LD), Meta tag optimization and Open Graph protocol, XML sitemaps and robots.txt configuration, Core Web Vitals and how they affect SEO, Mobile-first indexing requirements, Internal linking architecture, Canonical URLs and duplicate content handling. I also share SEO-specific Next.js configurations and real examples from client projects with measurable results.