Hi @LauraLincks
I remember going through posts in the community that mention large numbers in their implementation such as yours quite a number of times; furthermore, there is no set limitation to how big a DHIS2 project can be as long as the logic, design, and resources are properly implemented.
It’d be interesting to know why a program required this huge number of program indicators and whether there were alternative solutions.
However, regarding limitations, I don’t think there are any limitations in the app itself or DHIS2 but I do expected the limitations to be from the server side configuration or maybe the available resources to the instance.
The PDAC app is built by @plinnegan who is also active in the community and might give us a hint.