Case Study: Redesign of Svět Svítidel

We must admit, when a client informs us about an upcoming redesign, a slight chill runs through the team.

We become particularly attentive when the client in question is Donoci, whose Svět Svítidel ranks among the ten fastest Czech e-shops.

In this case, however, the redesign was successful, and we're delighted to showcase how a happy ending was achieved. Feel free to use our case study as part of your guide to a successful website overhaul.

Experienced web professionals know that redesigns come with a slew of risks. One of these is a potential slowdown, something we've witnessed many times, even though most major site overhauls aim to improve speed.

How Not to Botch a Redesign from a Speed Perspective?#

Looking back at the redesign process of Svět Svítidel, we can derive several recommendations applicable to virtually all major site overhauls.

1) Communication is Key#

The client informed us well in advance about the upcoming changes, allowing us to propose a comprehensive approach. We maintained ongoing contact and approached the project as speed consultants with proactive involvement.

2) Beware of Major Technical Changes#

The road to slow websites is paved with the good intentions of developers. Often, attempts to speed things up by switching to modern JavaScript frameworks result in the exact opposite. At Svět Svítidel, only minor technical adjustments were made by developers from Programie. We were informed of all changes, allowing us to plan accordingly.

3) Without Measurement, There is No Insight#

For clients with stable speed, we typically use monitoring PLUS to measure only synthetically and with CrUX data from Google. However, for major changes, we deploy detailed Real User Monitoring (RUM), which we did shortly before the redesign launch, giving us real-time data.

4) An Educated Team Handles It Better#

As you know, we emphasize Performance Culture and the education of clients and their developers. We've worked with Programie for a long time and know their people have learned a lot from us and can implement further speed improvements independently. For other clients, we recommend brief team training before major changes.

5) Do You Have Templates? And Can You See Them?#

The first feedback from speed consultants comes when the client has coded templates ready. We can evaluate them from a frontend performance perspective, preventing many issues from reaching production. The next phase is testing on staging, where everything is connected to the backend.

6) Time for Feedback Implementation#

We only see a site's true speed after it's live, as we need data from users. Clients often don't realize this.

Teams also tend to lack time post-redesign, especially for speed-related tasks, as they're catching up on other work. However, after launch, we usually provide the most tasks and feedback.

During the Svět Svítidel redesign, time for addressing speed-related details was planned. Success!

It Turned Out Well, Speed is Improving#

Overall, the metrics across the domain remained at their original levels, which is excellent.

There is one exception – the INP metric has started to improve. This is great because, besides being part of Web Vitals and thus impacting SEO and PPC on Google, we know from RUM analysis that this metric correlates with conversion rates for Svět Svítidel.

On some page types, INP improved by several tens of percent. Thanks to this, SvětSvítidel.cz is one of our first major client sites with no URLs requiring attention from an INP perspective, according to Search Console:

Adjustments in JavaScript have helped the INP metric, among others, allowing Chrome to use cache for a much larger number of visits when navigating through browsing history, a feature known as BFcache.

Our new report on Navigation Types nicely illustrates the increase in page views with BFcache support.

Acknowledgments#

In this project, we were pleased that everything went smoothly, with minimal involvement and cost on our part.

This is the result of long-term collaboration, approached constructively by all parties with the goal of maximizing web speed.

Our thanks go to the client at Donoci (Jakub Rejlek, Tomáš Mikletič, Monika Pilátová, Martin Šimko), to Programie (Petr Rzeplinski, Tomáš Vacho, David Kaleta, Pavel Kramný, and others), and also to Zuzana Šumlanská, who managed the whole process for us.

A nice article on Programie's website was also published about this redesign.

Tags:PageSpeed.czWeb PerformanceCase Study