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Technical

Website Performance Optimization

Client: E-learning Platform

80%

Faster load times

25%

Increase in conversion rate

40%

More user engagement

90

Google PageSpeed score

The Challenge

E-learning site was losing 30% of users during course preview due to slow loading. Course landing pages took 5+ seconds to load, causing visitors to bounce. Conversion rate was 2% (industry average: 5%).

The Solution

Performed full performance audit, implemented code splitting, image optimization, CDN caching, and database query optimization.

The Problem

The e-learning platform was built as a monolithic Next.js application with several performance issues:

  • •Course preview pages loaded in 5.2 seconds (industry target: <2 seconds)
  • •30% of visitors bounced before page fully loaded
  • •Conversion rate was only 2% (well below 5% industry average)
  • •Google Core Web Vitals showed poor performance
  • •Mobile performance was especially bad (7+ seconds on 4G)

They estimated slow page speeds were costing them $2,000+ in lost conversions monthly.

Diagnostic Phase

I ran comprehensive performance audits using Chrome DevTools, Lighthouse, WebPageTest, and GTmetrix:

Initial Metrics

First Contentful Paint (FCP)2.8s
Largest Contentful Paint (LCP)4.2s
Cumulative Layout Shift (CLS)0.18 (poor)
Total Blocking Time (TBT)350ms
Overall Lighthouse Score38/100

Root Causes Identified

  • 1.Large JavaScript bundle (850KB uncompressed) - No code splitting
  • 2.Unoptimized course preview images (4MB+ per page)
  • 3.Slow database queries on course listing (average 1.2s per request)
  • 4.No CDN caching - all requests hitting origin server
  • 5.Third-party scripts (analytics, ads) not deferred

Optimization Strategy

1. Code Splitting & Tree Shaking (Week 1)

  • • Implemented dynamic imports for course preview routes
  • • Split main bundle into: core (150KB), preview (200KB), checkout (100KB)
  • • Removed unused dependencies (saved 50KB)
  • Result: Initial JS bundle reduced from 850KB → 320KB

2. Image Optimization (Week 1)

  • • Converted all course thumbnails to WebP format
  • • Implemented responsive image sizes (mobile: 300px, tablet: 500px, desktop: 800px)
  • • Added lazy loading for images below the fold
  • • Compressed video thumbnails with FFmpeg
  • Result: Image payload reduced from 4MB → 600KB per page

3. Database Query Optimization (Week 2)

  • • Analyzed slow queries - found N+1 problem on course-instructor joins
  • • Added database indexes on course_id and instructor_id
  • • Implemented query result caching with Redis (5 minute TTL)
  • • Result: Database response time reduced from 1.2s → 120ms

4. CDN & Caching (Week 2)

  • • Set up Cloudflare CDN (free tier)
  • • Configured aggressive cache headers for static assets (30 days)
  • • Implemented cache busting for code changes
  • • Result: Reduced Time to First Byte (TTFB) from 800ms → 200ms

5. Third-Party Script Management (Week 2)

  • • Moved analytics script to defer loading
  • • Deferred ad network scripts until after main content
  • • Evaluated necessity of each third-party tool
  • • Result: Reduced Total Blocking Time from 350ms → 80ms

Performance Improvements

FIRST CONTENTFUL PAINT
2.8s
0.9s
68% faster
LARGEST CONTENTFUL PAINT
4.2s
0.8s
81% faster
TOTAL PAGE LOAD TIME
5.2s
1.1s
79% faster
LIGHTHOUSE SCORE
38
92
/100

Business Impact

Bounce Rate

30% → 12%

Fewer users abandoning during page load

Conversion Rate

2% → 5%

Now at industry average. Estimated $5,000+ additional monthly revenue

User Engagement

+40%

More users completing course previews and making purchasing decisions

SEO Rankings

Improved

Better Core Web Vitals led to improved Google search rankings (estimated +15% organic traffic)

Key Learnings

  • •Measure first: Without proper diagnostics, optimization efforts get wasted. DevTools and Lighthouse saved us from premature optimization.
  • •Images are the biggest win: Image optimization alone saved 3.4MB and improved LCP by 60%. Always start here.
  • •Small improvements compound: No single optimization was a silver bullet. It was the combination of 10+ changes that moved us from 38 → 92 Lighthouse score.

Key Learnings

  • AI accelerates development

    Using AI tools can reduce typical timelines by 50-70% without sacrificing quality when you know how to guide them.

  • Systems beat manual work

    Automation and workflow optimization multiply productivity. Even simple systems can save 10+ hours weekly.

  • Human judgment remains critical

    AI is powerful, but strategy, user experience, and decision-making still require human expertise.

Tools & Technologies

Next.js

Supabase

Vercel

AI SDK