Building to get a better understanding of how something like this would work. Example you as a new citizen in an e-gov country go to get your medical records and after going through the extensive process of vetting who you are and who your parents are and taking in all the necessary information etc you now have a medical record, Yipee! After doing that once all of your information is saved in the system indefinitely. Now fast-forward a few weeks later when you have to get your drivers license now the process will be streamlined because you wouldn't need to prove you are who you say you are with the usual documents since all of your latest information is already in the system the only thing left to do is pass the drivers test and get your photo taken since every government agency would have access to your basic information.
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Now security would need to be first priority in a system like this for obvious reasons, you'd want to log every thing an authenticated government agent does like basic CRUD on a persons information and give agency heads the ability to rollback changes to a person's information at any point in history that pertains to that specific agency etc. And there would also be an identity strategy beyond the basic 'person' information to allow a citizen to also utilize other e-government services online like applying for a business license, renewals etc.
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The project is structured in a DDD style with the agency / person being the domain but in a non-trivial version those domains would be completely separate projects with more fine-grained domains for a particular agency & person in a distributed system.