Hi, very interesting Certificate Service project !
It can be done with a network service directly issuing the needed certificates instantly.
Can be a tiny, fast and reliable service app :)
I'm a tester, so we can overcome easily the testing job also.
... with 25 years of experience on Networked Database A.I. projects analysis & development...
Based on my experience this can be easily achieved.
Simply give me more details and we will overcome this challenge, reaching together the best solution needed.
Feel free to contact me for any clarification or question that can get the success of your goal
Cheers
Gianni