I recently spent some time at my hometown checking some old pictures and notebooks I've got from my childhood, and then spent some time thinking about all my father did for a living, for us, and for all the people around him during his life time. This is a short story of what I know about him that makes me declare that he was an engineer, in the best meaning of the word. Read more...

If you are a programmer, you have dealt with persistence layers in many senses: RDBMS systemsFile systemsRemote storageJust memory...And if you are a programmer, you know that all those persistence layers have to be abstracted from the application's business logic. There are several techniques to achieve this:Data Access ObjectsMappersObject Relational MappingCQRS patternAll those techniques wrap your data from the persistence source you are using, because your application should have its own 'language'. Read more...

As a developer and Linux-user, I continuously change several configurations in my systems, some of the changes can include: Port-based services: When you have several web servers working on the same machine, you have to configure ports and alias addresses.Package sources: I just don't want to mess my apt-get and slapt-get sources configuration.Security: External services configuration, security configurations and system restrictions.Run levels: I like to have the services I use at system startup, the other ones can burn in hell. Read more...

I've been using this kind of PersistenceUnit creation for some unit tests, because they had to run along with some integration tests, and because of that the persistence.xml files were messing between them. So, how to create an EntityManager programmatically? Solution link: http://docs. Read more...

I've worked in some projects so far and I learned some things that can save you a lot of time even if they sound very expensive. These tips are meant for small/medium size projects, perhaps you can apply them to big projects, but I'm not sure. Revision control system from the beginning.Define your goals and milestones, even without dates.Define what you are going to build, with use cases or user stories, or just use whatever you feel comfortable with. Read more...

A few years ago I gathered this pagination component logic from a co-worker and changed it a little bit, adding some desirable functionality and reducing some external dependencies. I've used in several projects, web-oriented and desktop-based and it accomplishes its works, pagination. Today I spent a couple of hours configuring it for Maven Central, just to check if I could do it. So, here it is, my first component published on Maven Central that can be used if you want to. Read more...

For a while I've been reading about the term Software Archeology from different media channels and I find it very valuable. Especially if you are trying to do something interesting with your projects, in those cases is a very good idea to checkout some very well written applications. Rails If you want to see what Ruby can do, this is the project I recommend. It has several gems in it, including a very complete documentation. Read more...

I have been trying to port some work I've done in Java to Ruby, to see how it looks and how much code it would take. But in the way I found out that Ruby might not be the best option for this kind of situations. Let me explain it, this is my pseudo code: As you can see, the OrderSet has a collection of Order classes, but classes! Read more...

A short presentation I gave about Scrum, I've taken a lot of material from Jurgen Appelo's presentation.

I must admit that I'm being sleeping for a while, in my personal life, in my career and left behind the goals that inspired me just a year ago. But some things changed during the last two months, I started doing things that changed my life. Small things that I thought were lame and not worth doing, here is a list of them: I got high rates on my masters degree when I started losing interest on it. Read more...