Add tests to the courses.

For beginners the learning experience is a bit dull, a lot of videos, there should be more specific exercises, lots of small exercises to train specific things with pre-populated data.  

Like there is in the becoming a developer path but a lot more of them.
Please have a look at the Salesforce trailhead, and the exercises they make a user go through to get the points (more points if you do it right the first time as well!).

Many coding academies have challenges by making copies of airbnb application or something like that - that would make the experience more rewarding.
Note: there should be a video of someone making the exercise (ie. showing the way in case the user gets stuck in the exercise if they are longer challenges). 

It would help someone going through the whole OS ecosystem and the steps needed to be done for certain,  otherwise I listen but then I don't get to play (reinforce the learning).  

Changed the category to Training

For training purpose it would be nice to take a test exam before going for the real deal :)

Changed the category to Training

This is a good idea :-)

Good idea.

Yeah especially for the higher level exams it would be nice to see a test exam with a small sample of questions.

great suggestion!

Good idea!

I agree having sample tests for certification exams would be extremely helpful to confirm we are ready to pass the test the first time.  I see this was noted as "working on it" over a year ago, but I am not able to find any sample tests on the Training site.  Can someone please comment on the status of this request?  Thanks!

By now, most recent courses have short quizzes throughout the lessons to reinforce main concepts (and gamified), and most (not sure if all) certification exams have, as part of their Exam Details link, a smaller sample test with answer grid at the end.