SME

This is one very important abbreviation and a role hiding under these 3 letters. It means Subject of Matter Specialist. In software development, this is a person whose role is very important, especially in huge companies, with many horizontal layers of software. This person, SME, should know the some specific functionality - what were the requirements for that functionality, how does it work, how should it work, theoretical background of functionality, what customer wants to see in this functionality, what are the competitors solution looks like, which software components are used in this functionality, what are the components interfaces, how these components are set (configured) in order to provide this functionality, what is the flow of data, where are the logs of all components, how they can be read. Someone who can point in a component and said - this component has an error. Person who can orchestrate bug resolving, new features development.
And this person is very valuable in a fast growing company, where documentation can not follow the pace of the growth.