A process manager is an event sourcing primitive responsible for orchestrating long-running processes. The term "long-running" here applies to the fact that a process can span multiple commands and events, and does not refer necessarily to a span of clock time. Concordance maintains the internal state of a process manager while configuration declares which events start, advance, and stop a process.
The developer experience is continually improving and as it does, this page will contain a more in-depth discussion of building process managers in Concordance. Until then, please use the interbank transfer sample from the bank account demo as a template for building your own process managers.