The WordCamp Athens 2025 was held on November 8, 2025 at the OTE Academy facilities. TrustServers supported the event as a Premium Sponsor, demonstrating in practice its commitment to WordPress and open-source software.
Talks are the heart of every WordCamp, and in that context I had the pleasure of taking the stage to speak about a topic I constantly encounter in my work: WordPress Object Cache and whether it actually benefits us to make it persistent, using a Redis server for example.
The video of the presentation has been uploaded to WordPress.tv, so if you weren’t there or want to watch it again, you’ll find it at the end of the article.
A few words about the Persistent Object Cache
Object Cache is one of those topics where the solution is usually applied “blindly.” We hear that Redis helps with speed, so we install the corresponding plugin and start using it, without ever having measured whether it actually makes a difference in speed (before and after).
Object Cache stores the results of queries and other computations that are costly in terms of computing resources. The catch is that these results are lost as soon as the request finishes. Persistency changes exactly that: the data stay stored, usually on a Redis server, and remain available for subsequent requests as well. It sounds like an easy speed win, and that’s exactly where it gets interesting!
In the talk I explained what exactly the Object Cache is and how it works, what we gain by making it persistent, and what options we have for storing it. I also presented before-and-after measurements from enabling Redis, taken from real WordPress websites hosted on TrustServers’ infrastructure, along with ways to leverage it through code.
Does the Persistent Object Cache always make sense on a WordPress site?
I won’t spoil the surprise here! The answer needs a bit of discussion and some numbers. Both can be found in the presentation (in Greek):
A faster website with Persistent Object Cache: Myth or Reality?
You can also view the presentation slides (PDF in Greek).
A warm thank you to the WordCamp Athens organizing team for a flawless event, as well as to everyone who came to watch the talk in person. But I especially enjoyed the conversations that followed at our booth. Those chats, about real problems and real sites, are ultimately what makes a WordCamp worthwhile.
I’m already looking forward to the next WordCamp Athens. See you again next year, with new topics and even more conversations.
If you’d like to make your WordPress faster, we’d be glad to have you get in touch with us.
