Tardis: A website that boasts incredible performance

When Tardis needed a website that had far superior performance than its predecessor, we knew what we had to do. We had to scope competitors’ performance and optimise for Google’s Core Web Vitals.

The challenge

At the heart of Tardis’s strategy lies the need to lay the cornerstone of their company and brand profile online. One that targeted a range of sectors from construction to events organisers – this posed a unique challenge, with both industries boasting unique demands.
Extramile Digital’s aim was to create a dynamic space in which visitors were not only subject to great website UX but also actively engaged with Tardis’s offerings. To do that, we had to ensure that Google’s Core Web Vitals were not only met but exceeded. Rather than using Lighthouse for this, we used real-world CrUX data to prove our optimisations worked and worked consistently.

Good UX is essential for building long-term customer relationships and long-term return on investment.

The outcomes

The results that we generated eliminated slow load times, and we transformed the site from an average performer to a website that passed all of Google’s Core Web Vitals with flying colours – as this mobile Core Web Vital screenshot quite literally shows.

mobile CWV data

desktop CWV data

Eliminating the slowdowns and moving to green CrUX data is no mean feat. Our old data showed the site was struggling to load. This was especially apparent on Mobile, which, as we SEOs know, is Google’s priority, even in the B2B landscape.

After the launch, we saw massive improvements for mobile CWV across the board:

Metric	What It Measures (Simple)	Before Launch (Slow)	After Launch (Fast)
LCP (Loading Time)	How fast does the main content appear on screen?	~3.0 seconds	1.1 seconds (63% faster)
FCP (First Appearance)	How fast does anything at all show up on screen?	~1.7 seconds	1.0 seconds (41% faster)
CLS (Visual Stability)	How much the screen jumps around while loading.	~0.15 (Noticeable Jump)	0.02 (Perfectly Stable)

In the end, the new website has been officially recognised by Google as having exceptional Core Web Vitals on both desktop and mobile. For users, that means the site loads faster than ever and lends itself to feel smooth and modern. For the business, that means higher fundamentals for boosting keyword performance and smoother UX to conversions.

How we Achieved it

Caching is the Secret Weapon: We utilised full Page Caching. This means the site stops asking the database to build the page from scratch every time. Instead, it serves up a pre-made HTML snapshot immediately. This instantly brought down the Time to First Byte (TTFB), which is the necessary first step for a fast LCP.

The JavaScript Detox: This was our biggest win; we delayed JavaScript Execution. This pushes non-essential scripts – like tracking code, third-party widgets and non-critical tools – until the user actually interacts with the page. This frees up the browser’s main engine immediately.

Image Anchors: We made sure every single image, especially the hero banners, has defined width and height dimensions. This tells the browser how much space to reserve, eliminating layout shifts completely.