Object Oriented (OO) system development using middleware such as DCOM and CORBA has been utilised by online businesses to implement e-commerce systems. Recent studies indicate that online businesses are increasingly adopting and implementing e-commerce systems using Service Oriented Architecture (SOA) technologies. Limited research has been conducted in comparing these two architectures at development, performance and user experience (UX) levels, especially in the e-commerce domain. This paper presents a study that evaluated and compared SOA and OO implemented e-commerce systems from development and UX perspectives. Literature highlighted a number of differences between the two architecture styles from a development philosophy perspective. UX evaluation results indicated that users could not notice any differences between the two interfaces running on different background architectures. Eye tracking and task completion time results, however, indicated that the SOA back-ended interface took slightly longer to complete processing requests than the OO implementation.