Embodiments are directed to application development. A data model may include one or more complex field types that each include one or more other fields. A separate data object may be included for each complex field type that defines one or more characteristics of one or more other fields included in a complex field type. An application design window may include one or more complex fields for an application, such that each complex field is associated with a complex field type. The data model may be modified to include another separate data object for each complex field type that is associated with the one or more complex fields, such that item values corresponding to each complex field of the same complex field type are stored in the same other separate data object. The modified data model may be deployed to enable one or more application shells to execute the application.