[Review] A day at Voxxed Days Luxembourg

Voxxed Days Luxembourg

[Review] A day at Voxxed Days Luxembourg

Voxxed Days Luxembourg

Here is Olivier‘s feedback of this year’s Voxxed Days Luxembourg.

If you never went to Voxxed Days Luxembourg, here is my feedback, salt and humour included, but removable.  You know like the “Batteries included but removable” of modern technologies.

Voxxed Days is the “smaller” version of Devoxx as it’s a one day conference compared to the bigger format of 3 or more days. Devoxx is a conference by developers for developers. Voxxed Days’ look and feel is exactly the same though, and it is equal in quality to the “big” sister conference. The second edition in Luxembourg was held June 22.

You’re a dev, you should go: yes!

You’re not a developer: you are not concerned! Mmm… no, if you are not a horse with blinkers, you are concerned!

Here are the categories:

  • Architecture, Performance and Security
  • DevOps, Agile, Methodology & Tests
  • Alternate Languages
  • Java, JVM, Javas SE/EE
  • Web, HTML5 et UX
  • Big Data & Analytics
  • Cloud & Scaling
  • Future & Robotics
  • Mobile, IoT


Now tell me again you are not concerned. You cannot. I told you.

For only one day, there was a great selection of talks. Check out this year’s complete and detailed program. Tick all the talks where you are lost already after reading the title. Tick the talks that sound interesting. Remove the boring stuff, if any. Drop in a subject or two you’ve played with a bit or you’ve been exposed to. You know, so you can quit the room with a badass comment (“yeaaaaah, that wasn’t really interesting, he/she barely scratched the surface”) and that warm feeling you knew quite a bit. Confidence booster, I tell ya! Mix, filter, match, … you should end up with a full day’s worth of things to do. This was my day at VoxxedDays Luxembourg.


Woke up. This ought to be a good day. Queued a couple minutes to get in. Radar activated. Ah, familiar faces. Small talk mode on, not weather or traffic focused for once, but program centric: who is going to sit in which talk, last minute changes for some that get influenced, …

Time to get going: listening on all interfaces …


9:00 – Keynote.

Data, private data, data science, ethics, IT professionals’ role and position in today’s society. Serge Abiteboul explains that data analysis is not the niche of petabytes companies anymore, that it is done more and more, in many businesses, on whatever relevant data is collected. Data collection is more and more tailored for the information that is needed/requested/expected and goes beyond the purely technical metrics to verify service health or generate alerts and basic statistics.

We are going to be exposed, involved, maybe we’ll become actors of this transformation. As we might be the ones installing and tuning the tech bits enabling the gathering of information in otherwise boring data, we will have great power. And with great power comes great responsibility.

There are two side to the coin: the one that allows us to extract heaps of information and be greater, more efficient, faster, … and there is the side that is all about trends, behaviour, secrets, control … There is the data we acknowledge to give, the data that is collected from our actions (with or without us knowing about it), there is private data that we broadcast willingly or unwillingly.

We will have to think about ethics and the boundaries that are to be defined to make IT work for us, for the better, and not against us, for the worst or only for profit. We are all shaping the future and we have to think about it. Some can only see the darkness that could/can be unleashed and tend to err on the side of caution to say it mildly. Others promote the wonderful things and progress that could elevate us to new heights. What we want and how we want it is a decision to be made by all of us, not only IT people. These decisions will define the social rules of the future.

This talk really resonated with me as I’m getting more and more conscious about privacy, data, what data can tell, what you can make it tell if you are so inclined. Wholeheartedly recommended talk.


10:15 – SSL/TLS for Mortals.

I played with SSL/TLS, securing virtual hosts on Apache or Nginx, securing an Elasticserach cluster (now with X-Pack) or securing my own services with “let’s encrypt”. Maarten Mulders explained the concepts: public key, private key, encryption/decryption formula, singing, all from the ground up. I had to surf the web for quite a while before I could regroup the information to get a good picture. In this session, it was done progressively and it was easy to follow. For someone that had little or no knowledge, this session had all the information you needed to get going.


11:15 – Advanced search for your legacy app with Elasticsearch.

I installed an Elasticsearch cluster beginning of the year. I had not used Elasticsearch since installing an ELK stack a couple years back. I recently had to create a dashboard with Kibana, … This talk was right up my alley. It was a live coding session from David Pilato. He showed how Elasticsearch could be integrated with a REST application using Hibernate and MySQL. He explained the technical parts while modifying the application. After each modification, the search functionality was tested which led to optimisations. He showed how to code the integration of Elasticsearch but more importantly, what can be achieved and how to build complex summaries of data with Elasticsearch aggregations.


12:15 – Lunch break.

Time to walk around, talk, share, get feedback from friends about their experience, have a chat, get something to eat, collect stickers and goodies, …

I cannot emphasise how important it is to collect stickers. Stickers on your laptop will make you or break you, they define you. They will actually generate discussions. The more, the merrier! Be careful, the trendy stuff from two years ago can be out this year, so cover them stickers up with new ones quickly. Be fashionably geek! But I digress.

The break is a good opportunity to go through the booths. The “good ones” have retro games. That too is a current trend. Profit while it lasts! Kids that where not born at game release compete to win a prize: the biggest high score wins. If this is not a testament to the fun factor of these games, I don’t know what is. Or is it just the prize they are after. I digress again.

As there are small sessions even during lunch break, I attended one.


12:45 – Use your workstations as MESOS agents in 15 minutes.

I’m a big fan of containers, but I never played with MESOS. Benjamin Vouillaume and Jauffrey Flach say I can bootstrap a DC/OS platform in 15 minutes with boot2dcos that they have developed. I’m in! DC/OS is a distributed operating system based on the Apache Mesos distributed systems kernel. It enables the management of multiple machines as if they were a single computer. It automates resource management, schedules process placement, facilitates inter-process communication, and simplifies the installation and management of distributed services. Its included web interface and available command-line interface (CLI) facilitate remote management and monitoring of the cluster and its services. boot2dcos is used to automatically configure a cluster.

Benjamin and Jauffrey’s goal is to make it as simple and as fast as possible to create a cluster or add to an existing one. A use case for instance would be to use the company’s workstations at night time to leverage the usually unused power for compute or analysis tasks. With boot2dcos, the workstations that do email and whatnot during the day would be transformed into or added to a modern cluster during the night. I think it’s very clever.


13:45 – Migrating to Microservice Databases: From Relational Monolith to Distributed Data.

That presentation was packed with information and concepts. If I had to pick one presentation I would recommend over all others, this is it. It targets not only developers, but everyone because it shows what can be done to work more efficiently. In one hour, Edson Yanaga goes over batch size, deployments, blue green, stateless, stateful, strong consistency, eventual consistency, strong eventual consistency, CRUD, CQRS, event sourcing, microservices, distributed data, databases best practices, automation and migrations, and the quest for the holy grail: achieving zero downtime deployments. That presentation is a must see for anyone in IT thinking there must be a better way. Take an hour, watch it, share it, reflect on it, act on it!


15:00 – Multiroom sound system with Ansible and a few Raspberry Pi’s.

That was a nice refreshing presentation because instead of showing the perfect end product and skipping all that was complicated and went wrong, Jérôme Petazzoni and AJ Bowen did exactly the contrary: they explained how a simple idea took them down the whole rabbit. There is no way you cannot relate to that story in some form or another. I can guarantee that. If you tinkered with new concepts or edge tech, you know what I mean. When a demo is perfectly executed, you don’t know how much time went into it, how many failures before success. This time you will know, and there’s no complete success in the end either. If you follow the guy, you know he is skilled, which makes it even more funny, because you know, he did not let go. If you want to know about problems, issues, complications relating to a fun project, tune in, because usually, this is the stuff nobody talks about.


16:00 – Containers and configuration with git and confd.

I had played with confd a year ago to deploy a Consul cluster on Rancher. So I had a good idea of what to expect. But at the end of a packed day, I thought it would be wise to go see something I had played with. confd is a small Go program that is used to generate configuration files with Go templates. The configuration of your app goes into a key-value store, confd gets the values, generates the config file and your startup script waits for the config file to be available before launching the app. This is, in a nutshell, what Christophe Furmaniak explained in details during his talk. Even if you don’t use Rancher or containers, it’s a great way to handle application configuration.


17:15 – Functional Programming.

Last presentation of the day in the main room. This is usually fun and lightweight, plus I can use the “smart recreation time” right now to end the day with a laugh. Well, it was not funny. At least for me! I was not receptive to the subject, nor the way it was approached. I did not really care for a tutorial on monads, functors, encapsulation, … And frankly, from the reactions in the room, I think I was not the only one. I may be wrong. This is all subjective. Well, this is part of the game too. Sometimes, you just hit the wall, or you simply fall out because you used up all your energy for other subjects. Or you’re not interested, plain and simple.

18:15 – Quick talk with colleagues at my company’s booth. People are heading to the exit. Some are leaving, others are waiting for the shuttle to go to the “Meet and Greet”: networking around beverages. I’m tired and not a social guy anyway, so … bye, bye VoxxedDays, thanks, see you next year!


I had a great time and I’m thankful my company encourages us to go to such events. There are obvious patterns in the talks I chose. Maybe you would have gone to very different ones. And therein lies the beauty: everyone can choose his/her own path. The bad thing about these days is that you need to choose where to go. Everything is interesting depending on who you are and what you do, or what you would like to do. The good thing about these days is that you can expose yourself to a vast range of technologies and concepts in a very short period of time and get input from people that put in the hours on specific subjects and are able and willing to transmit their experience. It can be overwhelming but you get lots of pointers. It is up to you to follow up or not.


One thing is for sure: everyone learns something!


Maeva Pitou
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