I have been working hard on animated picoids, our next big feature, and figured out that continuing on the Node.js/Express.js path doesn't scale well. I'm not worried about the performance, it's just that this style of asynchronous nested functions combined with a truly terrible type system is causing a lot more headaches than it should, and stalls the development of new features.
In addition, I also spent two weeks relaxing because of the common cold, which also gave me time to think things over. After consulting a friend, I decided to go with Flask and began to port the server. Flask is a really neat micro-framework not so far away from the functionality that Express.js offers. As a bonus, everything is synchronous and works on Python, which feels just so much more comfortable and reliable.
I'm working a few hours every evening. About 60% of the present functionality has been restored. This weekend we'll roll out the finished port. Nothing should change for you as a user, but new features should roll in rather quickly in the following weeks.