While it's not a strict prerequisite, it is recommended that you earn your Microsoft Azure Fundamentals certification prior to training for your Azure role-based certifications.
The next logical step after earning your Azure Developer Associate certification is to earn your Azure Developer Associate certification (if you haven't done that already), then train for and pass the AZ-400: Microsoft Azure DevOps Solutions exam and add the Microsoft Certified: Azure DevOps Engineer Expert certification to your transcript.
Microsoft provides two re-certification options for those who want to demonstrate continues competence in these areas. You can demonstrate that you're staying current in the technology by either taking a re-certification exam or stay-current course within two years of earning your certification. As soon as you pass either the course or the exam, the expiration date on your certification will be extended two years from that date. For more information, please check out the FAQ on Microsoft's Certification Exam Policies page.