UI specialist exam is retiring this month and I was planning to prepare for this. So just wanted to know what course will be the replacement for this (like UI specialist 7.4) or will there be any replacement at all.
The UI Specialist course for v7.1 is still available in Pega Academy. However, the CUIS certification exam did expire in February 2019. If you are looking to take more recent content on UI, there is a course in Pega Academy called Designing a User Interface, on v7.3.1. New curriculum and certification exams are planned for v8 (on the roadmap), but have not yet been scheduled.