Do I need to solve the challenges at the end of each module to get a certificate?

Yes you need to, but in most cases there are very easy

Solving projects checks your understanding on the concepts that's why they are necessary

Julian Bents yes I noticed and now I have to redo these to get 100% completion.

I'm on module 5 but could only do the first 2 challenges. Are you sure they're necessary for certification? Doesn't seem realistic for a beginner's course

How long you think is a realistic time for a beginner with no coding background at all to finish this course with all the challenges?

This java course here isnt very big. If you learn every day 30 to 60 min you should have compmeted it in lass then 2 Weeks and if you are a beginner you can do the challanges at the end of the entire course

Was not the case some years ago.

Sonic it Was added a couple months ago

I strongly disagree. This course does not prepare you enough to solve these challenges. The only way to understand certain things is to go on youtube and search for tutorials explaining certain topics and trying to practice them on your own which takes way over 30min/1hour a day. At this point I'm just going on the discussion page and seeing what other people did

Same

In challange 3 you can do it with a char array and they explained it Luciana Bellott

Luciana Bellott I agree with you in this point