How Custom WordPress Development Increased Mobile PageSpeed by 61% and Improved Core Web Vitals

Case study: a custom WordPress rebuild took Dragonboat's mobile PageSpeed from 56 to 90 and LCP from 15.7s to 2.3s, with the exact fixes and before-and-after metrics.

Alison Iddings

Oct 30, 2025 11 min read Updated Sep 7, 2026

To Top

Rebuilding Dragonboat’s WordPress site on a custom theme raised its mobile PageSpeed score from 56 to 90, cut Largest Contentful Paint from 15.7 seconds to 2.3, and eliminated Total Blocking Time entirely, without changing the design their customers already knew. This case study walks through what was wrong, what we changed, and exactly what moved in the numbers.

Client Overview

Dragonboat is a product portfolio management platform that helps organizations prioritize and deliver strategic initiatives. As their digital presence expanded, their website’s performance deteriorated, hurting user experience and search visibility.

Industry: SaaS, product management software
Location: Global
Website: dragonboat.io
Project type: Complete WordPress rebuild on a custom theme, with performance optimization

The Challenge: Critical Website Performance Issues

Dragonboat’s website had performance problems severe enough to threaten both visibility and engagement:

Slow load times, especially on mobile devices
Limited scalability, so traffic growth made things worse
SEO exposure, since Google’s Core Web Vitals are a ranking signal
A mobile PageSpeed Insights score of 56, well below the 90+ that a “good” rating requires

Google’s own mobile page speed research found that 53% of mobile visitors abandon a page that takes longer than three seconds to load. Dragonboat’s Largest Contentful Paint was 15.7 seconds.

The site needed a complete technical overhaul while keeping the design their audience recognized and trusted.

Our Approach: Rebuild the Foundation, Keep the Design

We rebuilt the Dragonboat site from the ground up on a custom WordPress theme engineered for performance, search, and scale. The strategy:

Preserve brand consistency while replacing the technical foundation underneath it
Follow WordPress development best practices with clean, efficient code and no page builder
Optimize every Core Web Vital: LCP, interactivity (measured then as FID, now as INP), and CLS
Build a scalable architecture on WordPress coding standards so growth does not degrade performance
Design mobile-first, in line with Google’s mobile-first indexing

Technical Implementation

Custom PHP theme development tuned for WordPress performance
Caching strategy and database query optimization
Image optimization with properly sized, modern-format images and lazy loading below the fold
Minified and consolidated CSS, JavaScript, and HTML
CDN integration for a global audience

These are the same steps behind our page speed optimization services; the difference on a rebuild is that we can fix the markup itself rather than working around it.

The Results

Mobile PageSpeed Insights Score

Before: 56 (Poor)
After: 90 (Good)
Improvement: 34 points, a 61% increase

Core Web Vitals and Lab Metrics (Mobile)

Metric	Before	After	Improvement
First Contentful Paint (FCP)	8.1s	1.0s	87.7% faster
Largest Contentful Paint (LCP)	15.7s	2.3s	85.4% faster
Total Blocking Time (TBT)	130ms	0ms	100% reduction
Speed Index	8.4s	2.2s	73.8% faster
Cumulative Layout Shift (CLS)	0	0	Held at zero

What the Numbers Mean for Visitors

First Contentful Paint improved by 7.1 seconds: content appears almost immediately instead of after an 8-second blank screen.
Largest Contentful Paint improved by 13.4 seconds: the main content lands in 2.3 seconds, inside Google’s 2.5-second “good” threshold.
Total Blocking Time eliminated: the page is interactive as soon as it is visible, which is what INP measures in the field today.
Speed Index improved by 6.2 seconds: the page looks finished 74% sooner.

Business Impact

Search Visibility

Core Web Vitals in the green remove a ranking headwind across every page.
Faster pages crawl more efficiently, so search engines cover more of the site per visit.
Mobile performance is the performance under mobile-first indexing; the mobile score is the one Google uses.

User Experience and Conversion

Lower bounce rates: Google’s research ties every extra second of load time to measurable abandonment.
Higher engagement: visitors read further and click more on pages that respond instantly.
Better conversion: Portent’s research found conversion rates fall sharply as load time rises past one second.

A Foundation That Scales

Because the custom theme carries only the code the site needs, adding pages, campaigns, and integrations does not erode performance the way it did on the old build. The same approach produced a 0.8-second LCP on Hoppr.ai and a 31-to-86 mobile score on TBG Homes.

Why This Works

The Dragonboat rebuild reflects how we approach every WordPress project:

Custom Theme Development

Every site gets a purpose-built theme for its own performance, functionality, and business needs, not a generic template with the extras switched off.

Performance First

Speed is designed in from the first line of code rather than bolted on with plugins afterward.

Code-Level Expertise

PHP, JavaScript, the WordPress REST API, and modern build tooling, applied to produce measurable results.

Design Preservation

Performance and brand identity are not a trade-off. The site can get dramatically faster and still look like yours.

Ongoing Care

Our WordPress care plans keep the site at this level as it grows, with updates, backups, and performance checks handled for you.

Is your site failing Core Web Vitals?

If your WordPress site is slow on mobile, failing Core Web Vitals, or struggling to scale, we will tell you where the time is going and what it would take to fix. Custom development that delivers results like these while keeping your design intact.

Book a Discovery Call

or call 919-200-0201