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JFokus 2024

13 Mar 2024

min read

Recently myself and two other Lunatech colleagues had the opportunity to visit JFokus. JFokus is a conference that is held annually in the first week of February in Stockholm, Sweden.

In this post I will discuss my general experience of the conference, followed by short discussions of two talks that I attended.

The Conference

JFokus is held at the Waterfront Conference Center in Stockholm, located almost on top of the Stockholm Central Station. Catering wise the quality is excellent and the supply of coffee appears to be infinite which is always a good thing. Overall attending the conference was a very smooth and comfortable experience. I would like to compliment the organizers and volunteers on the quality of the event!

Content wise a broad range of subjects is covered with a focus on java, the JVM, and the surrounding ecosystem. This year there were also a good number of talks discussing AI, both how to use it within your projects and how to use to it in your own coding process. With over 70 talks scheduled attending all the talks that look interesting is an impossible assignment! Luckily all the talks were recorded and are published on YouTube, you can find the link can at the end of this post. The first recordings were already online within a few days after the conference.

Talk: Tame Microservices with Contract Testing by Holly Cummins

Personally I have never worked with contract tests before and I was curious how they work. In the talk Holly gave a great explanation of why and when contract tests can be useful. A picture says more than a thousand words, and I think this graphic from her slides illustrates it perfectly.

Contract testing slide excerpt
Figure 1. Where contract tests fit

After this explanation she discussed Pact, a polyglot framework for contract testing. Pact helps with creating the contracts & sharing them between teams so that everyone always uses the latest version of the contract in their tests. This was accompanied by a very well done demo involving several Quarkus based Microservices and a frontend that showcased exactly at what service things started going wrong.

For me this talk gave me a good idea of where and how contract testing can be useful. You can see the full talk yourself on youtube:

Talk: How hacking works by Espen Sande-Larsen,

Espen gave a presentation on what hacking is, and is not. The talk started with some hollywood examples of what hacking is not; we are probably all familiar with some movie examples of "hacking". This was followed by a discussion of what the word "hacking" typically refers to these days: "Exploiting systems trough vulnerabilities". He even included a story of how he himself got hacked in quite an epic fashion in the past. So much so that apparently this hack is part of some University curriculums in Sweden to this day.

After this we moved on to the subject of prevention of hacks. Espen is a big proponent of Capture The Flag (CTF) exercises. In CTF exercises the participants have to hunt for a "flag" in software that has vulnerabilities on purpose. This type of exercise lets developers look at software from the other side and gives them the opportunity to become familiar with "the tools of the trade" of the hacker.

Hacking tools slide
Figure 2. The tools of the trade

Espen also demonstrated that CTFs can be great fun: During the talk he guided us through few exercises and it really made me want to try solving some similar exercises myself!

You can see his full talk at JFokus on youtube:

Check out other talks:

You can check out the other talks of the conference at the JFokus 2024 playlist on youtube. Also for most of the talks the slides have been made available on the JFokus website.