Software Specification Document - Solution Architect 

Software Specification Document is a document containing business requirements called functional requirements and technical details called non functional requirements. Functional requirements cover definition of project and project terms, for example defining type of accounts: User, Admin and different Roles that can be apply to User account, maybe: Manager, Accountant (Roles  define to what resources account has access, Admin will have access to everything, where account is used to authentication process, using two factor authentication (2FA) or one time passcode (OTP). In project implementation phase those information will be used to build permission framework. But there is much more, project domain terms must be defined, for affiliate marketing it could be Campaign, Brand, Product, for project from gaming domain this will be reward mechanism. 

 

Use cases represent concrete functional requirements(features). If You plan to create server side application like application programming interface (REST API) this is obligatory to make sure that there is an alignment about end effect between project owner and development team . In this situation another approach is to use OPEN API specification it is used to define server resources/endpoints, that will be latter used by other applications web, mobile or maybe IoT and other server side application.