Finally the Magento 2 Certified Professional Developer certification is here! Time to start studying. If you want to download the free study guide without going through all the marketing, click here.
The Magento 2 Certified Professional Developer exam, a primarily scenario-based exam, is designed to validate the skills and knowledge needed to customize Magento 2 in the areas of: UI modifications, database changes, admin modifications, checkout process customizations, order management integrations and customizations, catalog structure and functionality changes. This exam is for a Magento 2 developer who has a deep understanding of Magento 2 development concepts and experience (recommend 1.5 years) in implemementing and customizing Magento 2.
You can also dig deeper in the full developer documentation located here.