At present time, a few integration and e-service development projects were started in Latvia. One of them is Integrated State Information System (ISIS, Latvian abbreviation IVIS), which was started in January, 2006. Customer and provider of this project is the Secretariat of Special Assignments Minister for Electronic Government Affairs (SSAMEGA)). This project solution forms the infrastructure for e-service development. The infrastructure is already accessible for e-service designers and developers since the middle of 2007. There are more than 30 e-services, which were developed using ISIS infrastructure, already accessible for Latvian inhabitants on Latvian government e-service portal (www.latvija.lv). ISIS is based on Service Oriented Architecture (SOA) principles and includes many individual innovations and modern solutions. The paper describes development architecture and innovations, which are used in ISIS solution and in the current government projects.