The Full Form of CSSA is Certified Senior System Architect.

The Pega Certified Senior System Architect (PCSSA) certification validates the ability to use Pega to design and build for reusability across multiple lines of business. It includes applying best practices, understanding application debugging and performance tuning, and addressing security/access requirements in an application. The PCSSA version 8 exam includes scenario questions, multiple choice questions and drag/drop items. If multiple answers are required, the text states how many responses are needed. Pega Certified System Architect (P/CSA) certification in any version is required to begin the PCSSA certification program.

The Pega Certified Senior System Architect exam is proctored by Pearson VUE.
Users must create a Pearson VUE account if you do not already have one and register for the exam through the Pearson VUE site.
There are two exam delivery options:

• Take an exam at a test center, or
• Take an exam via Online Proctored delivery
  (e.g., in a quiet, uninterrupted room in your home or office, proctored via webcam).