Abstract: What are some issues with IaaS and PaaS? For example, even the architecture of IaaS and PaaS can be misleading. Better architectural view can emerge when we look at the global picture of cloud computing: from the client side of the cloud computing to the server side. According to [Dean & Ghemawat] in CACM 2008, Google processed over 400 PB of data on datacenters composed of thousands of machines in September 2007 alone. Using two case studies from end to end, we will illustarte the challenges from computing on such a scale. Bio: Dr. Liao received his bachelor's degree from National Taiwan University in 1991 and his MS and PhD degrees from Stanford University in 1995 and 2000, respectively. One passion of his is on the optimization of everything from a data center to a device. His related publication in the past six months includes "Machine Learning-Based Prefetch Optimization for Data Center Applications" in Supercomputing Conference in November, 2009 and "Taming Hardware Event Samples for Feedback-Directed Optimizing Compilation" in IEEE Code Generation and Optimization Conference in April 2010.