I've been trying to build real systems with Microsoft's Durable Functions. I've been utterly fascinated by the patterns that have emerged on some of them.
Watchdog Pattern: A orchestration needs to succeed. A watchdog entity checks up on it to make sure that failures are reported and dealt with appropriately (ie, refunding a payment if it fails catastrophically)
Circuit Breakers: Polly has their own implementation, but I found it easy enough to implement my own (don’t recommend in production, just use Polly)
No database: it’s a bit slow to get things done, but it’s amazing to create entities that don’t need to store state in a database. Paired with the watch dog pattern or preloading, you can have entities running “in memory” which may be faster than a dB lookup or the data could be projected to a db for analysis. I’ve been exploring this most recently.
Aggregate entities: these just count things, or store references to important entities that they count. This works amazingly well instead of COUNT DISTINCT queries.
