The Department of Social Protection (DSP) in Ireland is responsible for administering all state pensions, unemployment benefit and many other social benefit schemes - an enterprise that has seen dramatic, if unwanted, growth in recent times. It is progressively replacing all its huge mainframe-based enterprise systems with a brand new architecture. Unusually, at a time when 'service-oriented architecture' was all the rage, the DSP opted instead for a pure object-oriented architecture - and theirs is now very possibly the largest scale pure-OO system anywhere in the world.

Richard Pawson, who has been involved with the DSP for 10 years will present the business challenges that the DSP faced, the reasoning behind the decision to go for pure OO, the many technical hurdles that were faced along the way, and the results ('warts and all') - now that multiple applications are running live under the new architecture. Keywords: objects, domain-driven design, agile architecture, agile development, test-driven; Suitable for: Architects, Development Managers, Modellers