Complex sentence: O'Brien also said as a teenager he worked with Irish banks to install software and fix technical issues and that he participated in the 1993 International Olympiad in Informatics computer coding competition on behalf of Ireland.
Split into simpler sentences: O'Brien also said as a teenager he worked with Irish banks to install software and fix technical issues. O'Brien participated in the 1993 International Olympiad in Informatics computer coding competition on behalf of Ireland.