Hi Ajinkya,

Hope you are doing well !

Earlier we used to have mobile developer as a couse but now its been moved to specialization, So to do the mobile developer certification you need to first complete

Associate reactive developer certification which covers most of the part of Web and Mobile. once it reactive certification is done you can go ahead with mobile developer certification

You can refer to below Guided paths for quick reference.

https://www.outsystems.com/learn/paths/18/becoming-a-reactive-web-developer/

https://www.outsystems.com/learn/paths/1/becoming-a-mobile-developer/

Also you can check for the sample exam question and course details at 

https://www.outsystems.com/learn/certifications/ and click on exam details.pdf for further details

Happy Learning !

Regards,

Swapnil