There are two kinds of applications that will be deployed in the central instance. namely
State-specific services
General services or multi schematic services.
State-specific
The state-specific services are applications whose working logic depends on the state actors largely and are implemented or customized by respective states as per their needs. Like calculators of property, trade-license and so on.
There are exceptions to this like Persister and searcher who are core services but still be deployed as state-specific for their own reasons.
persister handles a lot of traffic so the deployment is replicated in each state namespace and can be scaled locally.
Each state VPC (namespace) will have its own schema in DB where its data is stored. The searcher will be deployed locally to access the schema specific data.
Multi-Schema
Services that will be deployed in the common namespace (digit) and can pass the control to services belonging to any namespace (state) and persists and access data from any schema belonging to different states.