Stencil Theme & Product Catalog Optimization for BigCommerce Store

The Challenge

Project Overview

Liz Mathe runs a BigCommerce store with a large product catalog. They needed speed optimization to improve the shopping experience and handle their extensive product pages efficiently.

With a large amount of products, the store's category and product pages were loading slowly. BigCommerce's platform constraints required creative approaches to optimization.

The Goals

Goals & Objectives

The primary goal of this project was to improve Google's Core Web Vitals, site speed, and overall user experience and usability.

Our primary goals were to:

• Reduce mobile LCP significantly
• Eliminate layout shift across devices
• Improve mobile performance score above 80

The Solution

Our Approach

A systematic, step-by-step process tailored to Liz Mathe's needs.

1. 1

   BigCommerce Audit

   Analyzed platform-specific performance constraints and opportunities.

2. 2

   Theme Optimization

   Optimized Stencil theme templates for faster rendering.

3. 3

   Product Image Optimization

   Optimized product images across the entire catalog.

4. 4

   Script Management

   Deferred and minimized third-party scripts.

5. 5

   Category Page Optimization

   Improved load times for product listing pages.

The Results

Outcomes

Core metrics that improved over the duration of the project.

• 72% Mobile LCP Reduction. Mobile LCP dropped from 15.6s to 4.4s, a 72% improvement.
• 88% Mobile TBT Reduction. Mobile TBT reduced from 170ms to just 20ms.
• 57% Mobile SI Reduction. Mobile Speed Index improved from 6.8s to 2.9s, a 57% improvement.

Lessons

Key Takeaways

• BigCommerce requires platform-specific optimization strategies.
• Large product catalogs need image optimization at scale.
• Category page performance directly impacts product discovery and sales.