From a developer perspective, service-oriented just means that you're offering/accessing functionality via a well-defined app-specific network protocol interface with a standard taxonomy/representation of cross-cutting concerns such as auth, transactions/compensations, message synchronicity and QoS semantics (eg. request/response, at-least once delivery etc.), most of which define the shape of your service implementation code fundamentally. For example, if you're operating under the assumption that no distributed transactions are available, you'll have to fold the necessary logic for restarting and state management into your application code.