In spite of recent advances in computing, many core business processes are batch-oriented running on Mainframes. Annual Mainframe costs are counted in 6+ figure Dollars per year, potentially growing with capacity needs. In order to tackle the cost challenge, many organizations have considered or attempted multi-year mainframe migration/re-hosting strategies. Traditional approaches to Mainframe elimination call for large initial investments and carry significant risks – It is hard to match Mainframe performance and reliability. Using Hadoop, Sears/MetaScale developed an innovative alternative that enables batch processing migration to Hadoop, without the risks, time and costs of other methods. This solution has been adopted in multiple businesses with excellent results and associated cost savings, as Mainframes are physically eliminated or downsized: Millions of dollars in savings based on MIP reductions have been seen – A reduction of 200 MIPS can yield $1 million in annual savings. MetaScale eliminated over 900 MIPs and an entire Mainframe system for one fortune 500 client. This presentation illustrates reference architecture and approach successfully used by MetaScale to move mainframe processing to the Hadoop platform without altering user-facing business applications.