Case Study: Web Performance Optimisation

The Client

UK-based client in the home improvement segment looking for improved web performance, better User Experience, and a higher number of leads.


• MS Windows servers hosting the production website and the User Acceptance Testing (UAT) site.
• The site is built with Sitecore CMS.

The Website Load Problem

• Increasing traffic day by day
• Current server getting loaded with a need to employ bigger servers and load balancers
• Risk of the site getting attacked by hackers and malicious agents

The traffic to the client site was increasing by a big margin day by day and we found that the server was running at a high load condition.

We were also concerned about the security aspects due to the site’s popularity.

The Solution

We started considering the server upgrade as well as adding multiple servers to the mix along with a load balancer.

While these discussions were going on, we also evaluated Cloudflare, a powerful Content Delivery Network (CDN) with a built-in firewall.

After careful consideration, we opted for this solution and are extremely impressed with the performance so far.

Cloudflare not only works as a CDN, but it also acts as a proxy server thereby allowing us to retain the original URLs.

Many CDNs have their own independent URLs or require CNAME entries for a sub-domain causing a delay in loading the site assets.

Additionally, Cloudflare has a powerful Web Application Firewall (WAF) that keeps most hackers at bay. Its DDoS prevention record is also very impressive.

Benefits achieved with Cloudflare

  1. After the introduction of Cloudflare and tuning of its settings over a few days, we could achieve a very impressive 97.43% caching of the assets at the Cloudflare edge, on a consistent basis, thereby eliminating the need for any upgradation of the origin web server.
  2. We could use the HTTP/3 protocol, thereby helping us serve the pages in the fastest way possible.
  3. Cloudflare’s Web Application Firewall (WAF) is helping us to ward off hacking attempts.
  4. This site serves the UK geography only. Hence, we disabled access from several countries that could be hosting potential hackers.
  5. The landing pages for the ads are super-fast and help in improving the quality score thereby resulting in a better conversion rate.

Web Performance Optimisation

After Cloudflare was set up and running smoothly, we started focussing on the Web Performance Optimisation of the site.

We used several popular tools like Web Page Test, DareBoost, Page Speed Insights, and Lighthouse to analyse the page loading speed and Core Web Vitals of the important pages of the site.

As the site gets almost 50% of the traffic from mobile devices, we focussed on the loading performance on mobile devices. Once this can be improved, the performance on the better-powered desktops with faster wi-fi connections will be vastly better anyway.

As the site was built with Sitecore CMS, there were a few challenges in making Performance related changes. However, with small changes in the site architecture, we could employ changes in the technical part of the site (like the head section and the link headers) for optimised delivery.

We preloaded some assets, preconnected to some resources, and made other suitable changes.

Benefits Achieved with Web Performance Optimisation

With the above changes, we could bring down the Largest Contentful Paint (LCP) time and Cumulative Layout Shift (CLS) to acceptable limits as per the CWV guide.

One of the biggest speedups was achieved by optimising the various images with the help of TinyPNG. This reduced the size of each image by 30-50%. We also lazyloaded the images, videos, and iFrames below the fold and added priority hints for the hero images.

As a result, the LCP time came down from 6.x to 1.4 secs.

Core Web Vitals

We need to do more work on the Total Blocking Time (TBT) as we have a large number of 3rd party scripts that are causing the TBT to remain high. We are presently considering employing Partytown or Cloudflare Zaraz to tackle this metric.

Early hints effect

We also activated the Early Hints (response code 103) feature due to Cloudflare’s support for it as we already had the link headers being sent from the server. This helped us load the critical assets much more quicker.

The Way Forward

As mentioned above, we have to bring down the TBT to the CWV-suggested maximum. We will also keep monitoring the performance metrics to avoid any regression of the same.


We have found that by employing the right tools for the analysis and solution phase, and a holistic approach, the website can deliver lots of benefits to the business in respect of cost-saving and performance.

One needs to keep experimenting and stay on top of the latest developments to get top-notch results from the websites, whether these are lead-generating or eCommerce sites.

What about you?

If you are interested to get similar performance uplift for your website, please contact us with your website URL and we will be happy to do a preliminary analysis and discuss how we can improve your website’s performance in a similar way.

We need Web Perf Optimisation too!