Review IBM’s architecture center here->

https://www.ibm.com/cloud/garage/architectures

Pick one of the architectures based on your interests.  There are many to choose from including Security, Cognitive, and Analytics…

some possibilities-> 

https://www.ibm.com/cloud/garage/architectures/public-cloud/reference-architecture

https://www.ibm.com/cloud/garage/architectures/dba/reference-architecture

https://www.ibm.com/cloud/garage/architectures/cognitiveArchitecture/reference-architecture

Thoroughly explore that particular architecture and related assets (videos, github, etc…) Then writeup a one page summary of what you liked, didn’t like, etc… articulate what you learned deep diving the RA.