Example methods and systems are directed to a staging engine. A system may comprise two computing devices. The first computing device may be accessible to a plurality of users. The second computing device may be inaccessible to the plurality of users, but accessible by the first computing device. The first computing device may cause a user interface (“UI”) to be presented to a user accessing the first computing device. The UI may include data retrieved from the second computing device and may be operable to store data. The data entered into the UI for storage may be incomplete relative to the data structures expected by the second computing device. The first computing device or the second computing device may stage the data until additional data that completes the expected data structures is received. After the expected data is complete, the data may be stored.