For businesses relying heavily on online visibility, partnering with a Search Engine Optimization (SEO) agency is often seen as a practical and strategic move. However, when that agency overlooks crucial ranking factors—such as mobile optimization and page speed—the consequences can be dire. In an increasingly mobile-first world, even well-established websites can see a dramatic drop in search engine rankings due to poor technical performance. This article covers a real-world case study where a company saw its search rankings plummet, only to make a strong comeback by addressing one of today’s most essential ranking factors: Core Web Vitals.
TL;DR
The company initially suffered ranking losses and traffic declines as a result of their SEO agency neglecting mobile and page speed issues. After a comprehensive technical audit uncovered problems with Core Web Vitals, the business took targeted action to improve LCP, FID, and CLS metrics. Within weeks of implementation, their rankings began climbing back, traffic recovered, and user engagement improved significantly. Ensuring your SEO strategy includes mobile-first and performance-centric optimizations is not optional in 2024—it’s a necessity.
The Overlooked Essentials: Mobile and Page Speed
When the client hired their SEO agency, the initial results seemed promising—keyword growth, structured on-page content, and increased domain authority. But by the second quarter, they began noticing something alarming: their rankings on mobile started to degrade, particularly for core money keywords. At first, it was dismissed as algorithm volatility. But as it persisted, the real problem became apparent—their mobile performance and page speed were terrible.
Mobile-friendliness and fast-loading pages are not optional anymore. Google’s transition to a “mobile-first index” means that mobile performance is no longer just part of the game—it is the game.
Warning Signs the SEO Agency Missed:
- Long page load times, especially on mobile devices
- Unoptimized images causing poor Largest Contentful Paint (LCP)
- Excessive third-party scripts delaying interaction (FID)
- Layout shifts damaging visual stability (CLS)
- No prioritization of Core Web Vital scores in reports
Google Search Console and PageSpeed Insights were clearly flagging issues, but they weren’t addressed by the SEO agency, which focused solely on link building and keyword content. This created a massive blind spot.
Conducting a Technical SEO Audit
When the company finally engaged a technical SEO consultant, the first course of action was a full audit. Tools like Google Lighthouse, WebPageTest, GTmetrix, and Chrome’s DevTools were employed to dig deep into the pages’ performance metrics. The results were sobering:
- LCP: Above 4.5 seconds (Ideal: <2.5s)
- FID: Over 300 ms (Ideal: <100ms)
- CLS: Exceeding 0.25 (Ideal: <0.1)
These factors collectively contribute to Core Web Vitals (CWV)—a set of user-centered, real-world stats that Google uses to grade the performance and usability of a site. Failing these metrics directly impacts rankings, especially post-algorithm updates like Google’s Page Experience signals implementation.
The audit also revealed that images were not compressed, font files were blocking rendering, and server response times were abysmal. There were no fallback solutions for content failure, nor any lazy loading implemented for offscreen assets.
Steps Taken to Fix Core Web Vitals
With the damage identified, the company’s in-house development team—now working in alignment with the new SEO consultant—took actionable steps. These were not just patches but structural enhancements designed to improve real-world performance metrics.
Optimization Tactics Implemented:
- Image Optimization: Used modern formats like WebP and added SVGs for simple icons
- Server-side Improvements: Migrated to a faster hosting provider with better CDN integration
- Font Loading: Fonts were self-hosted and preloaded to reduce render-blocking
- Code Splitting: JavaScript was broken down into manageable chunks
- Lazy Loading: Implemented for all non-critical images and iframes
- CLS Fixes: Set explicit sizes for images and containers to prevent layout shifts
All changes were rolled out in stages, followed by rounds of testing via Lighthouse and field data from the Chrome User Experience Report (CrUX).
Observed Results: Rankings Rebounded
Three weeks post-implementation, traffic and rankings began to recover. PageSpeed Insights showed marked improvement across mobile scores, with all key pages moving into the ‘green zone’ for CWV metrics. Even more telling, bounce rates declined, and the average session time increased by 30%.
By Week 6, the site regained its top 10 position for all previously lost keywords. Month-over-month organic traffic saw a 45% boost. And Google Search Console began reporting a higher percentage of pages as passing CWV assessments.
Key Wins Achieved:
- 30% improvement in mobile page speed
- 45% increase in organic traffic within 60 days
- 150% improvement in user engagement metrics (session time, pages per visit)
- Recovery and growth in keyword rankings
For this business, resolving Core Web Vitals was not merely a technical exercise but a strategic maneuver that realigned their digital presence with Google’s current ranking criteria.
What This Means for Your SEO Strategy
If your current SEO agency isn’t prioritizing mobile experience and technical speed benchmarks, you may be sitting on a ticking time bomb. Google continues to double down on user experience as a critical factor in ranking websites competitively.
A “content-first” or “link-first” strategy is insufficient without the performance backbone to support it. Mobile performance, page speed, and CWVs aren’t just for developers—they’re KPIs every digital strategist should embrace.
Even well-optimized content will fail to shine if it loads slowly or performs poorly on mobile devices. As this case study demonstrates, catching and correcting these issues early can mean the difference between failure and success in the search engine results pages (SERPs).
FAQs
What are Core Web Vitals?
Core Web Vitals are a set of specific factors that Google considers critical in a webpage’s overall user experience. They include Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS).
How can I check if my site has page speed issues?
You can use tools like Google PageSpeed Insights, GTmetrix, or Lighthouse (built into Chrome DevTools) to analyze your site’s performance and identify any issues affecting page speed.
Is mobile optimization really that important?
Yes. Google uses a mobile-first indexing approach, meaning it primarily uses the mobile version of a site’s content for indexing and ranking. A poorly optimized mobile site can severely impact your visibility and traffic.
How long does it take to see results after fixing performance issues?
While every case is different, many businesses start seeing improvements within a few weeks to a couple of months. Google’s indexing and re-evaluation cycles determine the speed of change in rankings.
Do all SEO agencies handle technical issues?
No. Many SEO agencies focus solely on content creation and link building. It’s important to find an agency or consultant that understands technical SEO, especially around performance and mobile metrics.
Can I fix Core Web Vitals myself?
Some improvements, like compressing images or choosing a better host, are user-friendly. However, more complex fixes like code splitting or server-side rendering often require development expertise.
What’s the cost of fixing these issues?
Costs vary depending on the complexity of your site and the extent of optimization needed. Small improvements might be free or low-cost, while major fixes could involve hiring developers or moving to advanced hosting options.