| # | Diagram | The question it answers |
|---|---|---|
| D1 | Request Flow | What is the path of a request? What is the latency at each hop? |
| D2 | Data Storage | Where is all the data? What is the consistency model for each store? |
| D3 | Event-Driven / Async Coupling | What are the asynchronous dependencies and their delivery guarantees? |
| D4 | Data Pipeline | How does data flow from raw events to queryable results? What is the freshness? |
| D5 | Distributed Coordination | Where does the system require multiple nodes to agree? What happens during a partition? |
Each diagram type reveals one failure surface that the others cannot show. Draw all five; gaps in the diagrams are gaps in the design.