Jfokus 2015 main takeaways

The biggest Java conference in Sweden, Jfokus, wrapped up a three day conference on Wednesday. This was my fifth consecutive one and I thought it was the best in recent years. In this blog post I’ll summarize my main takeaways.

During the first day, the tutorial day, I truly enjoyed Ken Sipe from Mesosphere and his talk “Docker at Production Scale”. It was supposed to be a tutorial but it wasn’t focused on one subject, which one might expect from the title. The talk was divided in several parts where he first started talking about infrastructure in general, what’s problematic in today’s datacenters regarding resource consumption etc. He then gave a good intro to Docker, where even I who have been using Docker on a day-to-day basis during the last two months learned a couple of new things. The last part of the talk focused on Apache Mesos, which problems it solves and how. He briefly also touched on subjects such as Service Discovery. For me, the main takeaway from this talk is that the way we structure our datacenters and our applications are definitely changing and that there is a lot of exciting technologies taking form in this area at this point of time.

Christian Heilmann held an interesting opening keynote where he talked a lot about mobile apps and their profitability. He pinpointed that many think apps are sure way to make good money, but in reality, that is not the case. Very few apps out of all apps in the marketplace are actually that profitable. Your company will have a greater chance of making money out of apps if targeting the enterprise customers instead of individuals. Enterprises are constantly looking for ways for their employees to be more efficient and certain apps could possible help them achieve that. Individuals are also very conservative now days when it comes to installing new apps. Most people just go with the apps they have and install one or no new app per month. He had some interesting figures backing up those statements.

A great talk was “Thinking fast and slow in software development” by Daniel Bryant. His talk was based on the book Thinking fast and slow by Daniel Kahneman, but applied to software development. One good quote from this talk was “look for actual problems instead of solutions”. As developers we tend to start elaborating solutions instead of trying to understand the actual problem. Are we really understanding what the actual problem is? Or do we just think we know what the problem is when in fact do not? He also mentioned that some of the most common factors for failures in software projects (source IEEE) is poor communication among customers, developers and users, the use of immature technology and sloppy development practices. These are things that we definitely could do better at in our industry! There is no reason why we should accept this happening. We should all care more about software craftsmanship.

Jeremy Deane held an interesting presetnation on concurrent processing techniques using e.g. plain java.util.concurrent techniques and actors. He had a few good tips on how to decouple a web service which under the hood depend on a slow responding third party web service by making the communication in between them asynchronous. All of his examples can be found in his GitHub repo.

As usual at Jfokus, Arun Gupta presented what’s to come in the next Java EE version, in this case Java EE 8. Focus will be to improve the new features introduced in Java EE 7 to make them more usable. Support for HTTP 2 and HTML 5 will be added to help those technologies gain traction. Servlet 4.0 will be introduced as well as MVC 1.0. JAX-RS, JMS and JSON APIs will also get facelifts. The Batch processing API will not be tied to Java EE only but will in the future be available in conjunction with Java SE as well. Obviously Java EE 8 will contain improvements for the new language features introduced in Java 8, such as functional interfaces etc.

The second day kicked off with a talk by Jez Humble called “21st Century Software Delivery”. He really put emphasis on how important continuous delivery is along with continuous experimentation. As an industry, we are bad at experimenting. We try to build this big thing that we think our customers want (but which we don’t really know). Instead we should try out the thing we’re building in a small scale first, not only as a protype but a fully functional, nice and shiny feature that the customers will appreciate, but with very limited scope. We can then measure how well this experiment turns out by conducting A/B testing and comparing the analytics for this feature. Should we continue to build on top of that experiment or not? You wouldn’t go out to build a very large complex building without building it in small scale first and to assure that techniques and functionality is matching the expections. We should do that in software development as well.

Jez Humbles second talk, on automated acceptance testing was valuable. For me, who am passionated about delivering quality software, there wasn’t much new in his content but it was still refreshing to get reminded on why we actually want to do testing in a certain way, even though you might do it already. Most people have probably encountered flaky tests. Those tests that for one reason or another goes red with or without an apparant reason, just to go green in a build later containing a totally unrelated code change. Flaky tests leads to less confidence and trust for the tests which eventually leads to people ignoring them or not even running them at all. One interesting technique to battle flaky tests is to move known flaky tests to separate suite, which is to be run separately (preferrably after) your actual suite. Then, you can remain confident about your test suite always being reliable. When a flaky test has become stable again, it should move back into the main suite. It is important to remember that test suite shouldn’t be static. Tests should come and go and be moved appropriately alongside the codebase development. Do also not be afraid to actually delete tests that no longer brings value. We are horrible at identifying and actually removing those tests.

In between talks I also enjoyed meeting a lot of people I’ve worked with in various projects throughout my career. Always a real pleasure to catch up with old friends as well as getting to know a few new ones as well. I also got a brief chat with Jez Humble regarding continuous delivery and strategies for balancing between maintenance and development of new features in highly autonomous teams with end-to-end responsibility, a discussion which was very much appreciated. Even though the vast majority of sessions were awesome, I almost wish there would have been some more breaks as well so I could have had the opportunity for even more socializing.

All in all, a great event. Thanks to everyone involved in organizing this event and to all the speakers and attendees. See you in 2016!

Tommy Tynjä
@tommysdk