I have a similar background and am also working as enterprise Java Dev. Financially, I don't think that it is a smart idea to transition at the moment (at least

I have a similar background and am also working as enterprise Java Dev. Financially, I don't think that it is a smart idea to transition at the moment (at least in germany, where I live). Java developers still seem to have the highest salaries, the most job offers and the best outlook in general. There are various interesting technologies that COULD replace Java or at least JEE in the future, and it is certainly a good idea to learn them or do projects in your spare time. But beside Java, I don't think that there is any technology that you can be sure that it will be still around in 5-10 years. If you are just sick of Java and need some change, then try to find a new job where you can work with whatever you like. Java changes pretty slowly, and you can still change your mind a few years later and find a Java job. But if you need to decide for a language as a career-choice, stick with Java, at least for a few more years.