Introduction
In a case study aimed at improving the load speed of United Arrows CO., LTD.'s e-commerce site, a significant improvement of 934 milliseconds in LCP (Largest Contentful Paint) on product detail pages and 1,119 milliseconds on product listing pages was achieved. Speed Kit is a solution designed to optimize page speed without major changes to existing web systems. The unique caching technology is especially effective for e-commerce sites with a large number of images and content.
The experiment, which involved 22.1 million page views, showed substantial improvements on key pages in the checkout process. The results confirm that reducing page load times lowers the risk of bounce and enhances the overall shopping experience. Speed Kit was developed in collaboration with the University of Hamburg and is already successfully deployed on major European e-commerce websites. This pilot project was a significant step in testing its effectiveness in the Japanese market.
In this article, we present the specific measures taken to optimize page speed using existing systems and the impact they had on website performance.
“After implementing Speed Kit, we observed a trend towards improved conversion rates, particularly in transitions from product detail pages to checkout.”
Challenge
Solution
Page load speed directly impacts bounce rates and conversion rates on e-commerce sites. According to a study by Nielsen Norman Group, users lose interest if a page takes more than one second to load, and if it takes more than three seconds, many users abandon the site.
The e-commerce site of United Arrows also faced the challenge of improving load speed, particularly on pages with a large number of product images such as product listing and product detail pages. The existing system had limitations in image optimization and content delivery efficiency, prompting the consideration of Speed Kit as a solution.
Speed Kit is an official ACE eligible technology partner and independent software vendor (advanced tier) of the AWS Competency Partner Program "Accelerate" as well as the Workload Migration Program. Our technology is powered by 13 different AWS services:
- Elastic Kubernetes Service (EKS): We use EKS to schedule and orchestrate our Speed Kit applications on EC2 instances.
- Simple Storage Service (S3): Speed Kit stores cached assets in S3 buckets. Additionally, we store RUM (Real User Monitoring) and PI (Performance Insights) data in S3 buckets for analytics purposes.
- Elastic Compute Cloud (EC2): Our workloads are hosted on EC2 instances, as managed through EKS.
- Kinesis Data Streams: Kinesis Data Streams are used to ingest RUM and PI data from Speed Kit, which is then consumed by Amazon Managed Service for Apache Flink. Fastly also streams access logs to our Kinesis Data Stream, which are similarly consumed by Amazon Managed Service for Apache Flink.
- Athena: We use Amazon Athena to query data stored in AWS S3 buckets, enabling performance insights and asset preloading.
- Elastic Container Registry (ECR): Docker images are stored in ECR and deployed in our Kubernetes cluster, which is managed by EKS. For third-party application images, we use the pull-through-cache feature of ECR.
- Elastic Container Service (ECS): We build Docker images using a service hosted on Amazon ECS.
- Route 53: Route53 is used to manage DNS records.
- Simple Email Service (SES): We use SES is used for sending transactional emails.
- Managed Streaming for Apache Kafka (MSK): We use MSK to facilitate consuming and producing custom event records for different applications.
- DynamoDB: Speed Kit uses DynamoDB to store information related to our predictive preload feature.
- Lambda: We use Lambda to pre-render client side renderd pages to make that actual server side rendered.
- ElastiCache (Redis OSS): We use ElastiCache to store our Bloom filter, which checks whether an asset is present in our cache.
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Click the image to open the architectual diagram of Speed Kit with AWS
Results
Pilot Project Results: Significant Improvements on Product Pages
From October 19 to November 7, 2024, the effectiveness of Speed Kit was tested using 22.1 million page views. The results showed significant improvements, especially on product pages.
- On the product detail page, the Largest Contentful Paint (LCP) improved by 65%, from 1.447 seconds to 0.513 seconds, ensuring much faster delivery of the main content to users.
- The mobile metric “First Contentful Paint” (FCP), which is particularly important for mobile users, improved by 71%, from 1.309 seconds to 0.325 seconds, drastically reducing initial load times.
Sustainable Speed Optimizations for Long-Term Success
It is crucial to view speed improvements as an ongoing process that is regularly updated and optimized, rather than a one-time measure. Particularly on e-commerce sites, content is continuously updated with new products and initiatives. Therefore, it is essential to implement a system that not only maintains the improvements in load speed but also continuously optimizes them.
The United Arrows study demonstrated that Speed Kit can be implemented without making major changes to existing systems. This allows for continuous speed improvements without disrupting daily operations. During the experiment, compatibility with existing tools such as A/B testing tools was confirmed, ensuring seamless integration.
Another key factor is continuous system performance monitoring. Our 24/7 monitoring system allows early detection of any speed degradation, enabling prompt action. Additionally, quarterly performance reviews help identify new optimization opportunities and provide actionable recommendations for further improvement.
By combining technical compatibility with an operational support system, improved load speed can be established as a long-term competitive advantage, rather than a short-term fix. The ability to maintain performance even when introducing new features or running large campaigns is particularly valuable.
Impact on User Behavior: Faster Pages Lead to Better Conversion Rates
As part of the study, a detailed analysis was conducted to measure the impact of faster page load speeds on user behavior. A clear correlation between page load speed and conversion rates was found.
After the implementation of Speed Kit, improved conversion rates were observed on product pages, particularly from the product detail pages to the checkout. A positive correlation was found between faster load times and higher conversion rates, with the tendency that conversion rates improve as page load speed increases.
A similar trend was also observed in the add to cart rate. Faster page load times help users add items to their carts more easily, leading to increased purchases.
The effect was especially pronounced for mobile users. Previously, fluctuations in load speed due to varying network conditions posed a problem, but the introduction of Speed Kit allowed for more stable load speeds, greatly improving the shopping experience for mobile users.
These results are consistent with industry-wide findings. SpeedHub, a project from Google, the University of Hamburg, and Speed Kit, shows that improving page load speed results in higher conversion rates.
A 61% improvement in LCP was also observed on product listing pages. Despite the large number of product images on the page, it now loads smoothly, allowing users to search for products effortlessly.
Key Considerations for Businesses Looking to Optimize Speed
Google's standard for “good” speed is an LCP of 2.5 seconds or less. However, for e-commerce sites with many images and rich content, achieving this standard is challenging. Displaying high-quality product images is crucial, especially on product detail and product listing pages, and currently, nearly 30% of e-commerce sites in Japan have an LCP of over 2.5 seconds.
For companies facing these challenges, or those seeing potential for improvement in page load speed compared to their competitors, Speed Kit could be an effective solution. The United Arrows case study showed how the company utilized its existing system to achieve a significant 65% improvement on product detail pages and 61% on product listing pages.
Businesses in the following situations can particularly benefit from faster page speeds:
- Pages with a mobile LCP of over 1.0 second
- Long loading times for product images that users have complained about
- Aiming for incremental improvements without major system changes
- Looking to improve their Core Web Vitals score
If you’re considering implementing Speed Kit, we recommend first measuring your current performance. By using data from the Chrome User Experience Report (CrUX) and Google Search Console, you can identify pages or areas in need of improvement. By incrementally testing the most important pages, you can potentially achieve effective speed improvements.
Summary: Long-Term Improvements with Speed Kit
The United Arrows pilot project demonstrates tangible results in improving e-commerce site load speed and illustrates how these improvements can be achieved. The 65% improvement on product detail pages and 61% improvement on product listing pages are remarkable successes.
More importantly, these improvements were achieved using existing systems. With stable operations through a 24/7 monitoring system and a process for continuous performance improvements, these optimizations can be sustained in the long term.
E-commerce companies can effectively improve their site speed by testing the most important pages first. Improving page load speed is a key factor for business growth through enhanced user experience.
