This challenge seems a bit over the top. The task is to write a fully functional service for creating a photo mosaic service that accesses third party apis for sourcing the photos. Constraints are that you are not allowed to use any libs from outside the include standard library (though you are expected to write tests using some tool the challenge author is apparently trying to push)... The whole things has to be deployed and publicly accessible.<p>Seems like quite a bit of work for the chance of winning a bunch of ebooks.
This seems more like creating an entire service from start-to-finish rather than an exercise on learning a language. I appreciate the authors are likely trying to do this because the exercise touches on so many different areas, but personally I'd be put off by this, when learning it's always more enticing to go for bite-size challenges, so you can see progress easier and create milestones/goals.