SEO for Developers
Technical SEO essentials: performance, Core Web Vitals, schema markup, and optimization for search engines.
SEO is Not Just Content
Search engines care about technical implementation. A well-built website ranks better than a poorly-built one with the same content.
This guide covers the technical SEO work that developers need to know.
Core Web Vitals
Largest Contentful Paint (LCP)
LCP measures when the main content loads. Target: under 2.5 seconds.
- Optimize images (use WebP, compress)
- Minify CSS and JavaScript
- Use a CDN for static files
- Remove render-blocking resources
Cumulative Layout Shift (CLS)
CLS measures visual stability. Elements shouldn't move around as the page loads. Target: under 0.1.
- Set explicit dimensions for images
- Avoid injecting content above the fold
- Use transform for animations (not position)
Interaction to Next Paint (INP)
INP measures responsiveness to user actions. Target: under 200ms.
- Break up long JavaScript tasks (use requestIdleCallback)
- Defer non-critical JavaScript
- Use efficient event listeners
Metadata & Tags
Title Tags
Keep titles under 60 characters. Include your target keyword. Make them compelling.
Meta Descriptions
Under 160 characters. Summarize the page. Include a CTA when appropriate.
Open Graph Tags
Add og:title, og:description, og:image. Controls how your content looks when shared on social.
Schema Markup
JSON-LD
Add structured data using JSON-LD. Helps search engines understand your content.
Common Schemas
- Article: For blog posts
- LocalBusiness: For local services
- Product: For e-commerce
- FAQ: For Q&A pages
Sitemap & Robots.txt
XML Sitemap
Create a sitemap.xml with all important pages. Submit to Google Search Console.
Robots.txt
Tell search engines which pages to crawl and which to skip. Disallow /admin, /api, etc.
Common Mistakes
Client-Side Rendering Everything
Use server-side rendering or static generation. Search engines have trouble with heavily client-side apps.
Duplicate Content
Use canonical tags for duplicate pages. Consolidate similar content.
Ignoring Mobile
Mobile-first indexing. If your site sucks on mobile, it ranks poorly.
Next Steps
Run your site through Google PageSpeed Insights. Fix the red items. Monitor your Core Web Vitals over time.
Key Takeaways
- •Practical tools and techniques you can implement today
- •Real-world examples from production systems
- •Common mistakes to avoid and how to fix them
Related Guides
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