I found it to be a bit of a pain juggling through the pages on Microsoft’s Learning Portal when looking up the different exams so I listed out direct links to each of the exam’s.
Certification and Exam offer’s – https://www.microsoft.com/en-us/learning/offers.aspx
Exam AZ-103: Microsoft Azure Administrator Associate – https://www.microsoft.com/en-us/learning/azure-administrator.aspx
Exam AZ-203: Azure Developer Associate – https://www.microsoft.com/en-us/learning/azure-developer.aspx
Exam AZ-301: Microsoft Azure Architect Design – https://www.microsoft.com/en-us/learning/exam-AZ-301.aspx
Exam AZ-300: Microsoft Azure Architect Technologies – https://www.microsoft.com/en-us/learning/exam-AZ-300.aspx
Microsoft Certified: Azure Solutions Architect Expert (Achieved after passing AZ-300 and AZ-301) – https://www.microsoft.com/en-us/learning/azure-solutions-architect.aspx
Exam AZ-400: Azure DevOps Engineer Expert (pre-req either AZ-103 or AZ-203) – https://www.microsoft.com/en-us/learning/azure-devops.aspx