In this chapter, we will examine some of the architectural features of the SOA Suite. We refer to them as advanced features because they are often ignored by developers, yet an understanding of how they work can give additional capabilities to our composite applications. We will begin by looking at how the BPEL component stores instance states during long running composite execution and then how it uses threads before moving on to examine where transaction boundaries occur. Finally, we will review how a cluster works, and how it may impact the way we design and build our composites. Clemens Utschig has been a great source of help in providing the information for this chapter.