After an analysis of the requirements and possible solutions we advised our client that creating a Google Add-on in this case would be the best solution.
To prepare the Google Spreadsheet to be integrated with Target Process
To implement push and pull functionalities
To assign users from Target Process to be responsible for particular tasks, bugs or user stories on Google Spreadsheet.
Ironbelly Studios a game development company, based in Montreal, Canada.
To ensure that each project in Target Process has only one unique spreadsheet attached to it, the ID of the spreadsheet and link to the spreadsheet are automatically saved in Target Process in custom fields associated to the particular project. Only project admin can detach a spreadsheet from the project the spreadsheet is attached to by deleting values stored in the custom fields of the project.
Pushing all of the entities from Google Spreadsheet to Target Process was developed with great care about what data should be protected from unintentional changes by users of the Spreadsheet (some fields were protected from being edited by users with limited permission). Progress of the pushing data process is also shown to the spreadsheet user (e.g. cells already pushed into the spreadsheet are marked in green).