Author
Sophia DuToit
Performance & Web Quality Engineer
Sophia obsesses over web performance, Core Web Vitals, and making the web faster for everyone. She contributes to open-source performance tooling and speaks at web performance conferences globally.
12 articles by Sophia DuToit
CDN Caching Mistakes That Make Fast Sites Feel Slow
Is your CDN actually caching your content? Learn why cache MISS responses happen, how query strings and Vary headers fragment cache keys, and how to verify edge performance.
Read articleHow to Use HTTP Caching Headers to Improve Real-World Performance
Learn how to use Cache-Control, ETag, Last-Modified, stale-while-revalidate, and shared-cache directives to improve real-world performance without breaking freshness.
Read articleWhy Your Open Graph Image Still Isn’t Updating on LinkedIn, Slack, and Facebook
Updated your social preview image but still seeing the old one? Learn how platform caches, CDN caching, and OG image URLs affect LinkedIn, Slack, and Facebook previews.
Read articleCLS Issues Caused by Fonts, Ads, and Hydration
Is your layout jumping unexpectedly? Learn how to fix Cumulative Layout Shift caused by web fonts, unreserved ad slots, and hydration mismatches in modern frontends.
Read articleLCP Debugging Checklist for Modern Frontends
Failing Largest Contentful Paint? Use this practical checklist to debug TTFB, resource discovery, fetch priority, render delay, and heavyweight hero assets in modern frontends.
Read articleA Practical Guide to Finding Real INP Bottlenecks in Production
Stop guessing why your INP is high. Learn a practical workflow for finding real interaction bottlenecks in production using CrUX, RUM, web-vitals attribution, and DevTools.
Read articleWebP vs. AVIF vs. PNG vs. JPEG: The 2026 Developer's Guide
Stop hurting your Core Web Vitals with oversized images. Learn the technical differences between AVIF, WebP, PNG, and JPEG, when to use each, and how to optimize for LCP.
Read article“Crawled – Currently Not Indexed”: When Google Visited Your Page but Still Said No
Googlebot crawled your page, but refused to index it. Discover the technical reasons why—from JavaScript rendering failures and soft 404s to canonical conflicts and thin content—and how to fix them.
Read articleHow Third-Party Scripts Kill Your INP and How to Fix It
Are marketing tags and chat widgets ruining your Core Web Vitals? Learn how third-party scripts block the main thread and how to fix INP using Web Workers, lazy loading, facades, and smarter execution.
Read articleXML Sitemap Best Practices for Modern, Dynamic Websites
Still using a static sitemap export? Learn the best practices for dynamic XML sitemaps — clean URL selection, sitemap indexes at scale, accurate lastmod, hreflang for international sites, and a validation workflow that catches problems before Google does.
Read article7 Critical robots.txt Mistakes That Are Silently Killing Your SEO
A misconfigured robots.txt file can block important pages or resources from crawlers without any visible error. Discover the 7 most damaging mistakes, why they happen, and how to fix them before they cost you rankings.
Read articleCore Web Vitals in 2026: What’s Changed
Google’s performance thresholds keep evolving. INP has replaced FID, LCP scoring has tightened, and CLS expectations are stricter than ever. Here is what developers need to know right now.
Read articleWant to audit your own project?
The same expertise behind these articles powers CodeAva's audit engine.