I understand that PAB is a backend that:
- provides a standardized environment in which Plutus applications run
- provides disciplined state management
- presents discoverable interfaces to the external clients
- tracks on-chain information for smart contract uses
- allows developers to work in an emulated or non-emulated environment
- deals with requests such as running contract instances, forwarding user input to these instances, and notifying these instances of ledger state change events
But is it just another piece of infrastructure we should consider in our solution or is it a service we can consume for example from a third party like Blockfrost?