flowchart TB subgraph DEPLOY["Deploy order"] direction LR D1["Gateway (first)"]:::dep D2["Processors
Termination Grace Period 60s"]:::dep D3["Summarizer"]:::dep D4["Stateless APIs & Dashboards (last)"]:::dep D1 --> D2 --> D3 --> D4 end subgraph ROLL["Rollback order"] direction LR R1["Stateless APIs & Dashboards (first)"]:::rb R2["Summarizer"]:::rb R3["Processors"]:::rb R4["Gateway (last)"]:::rb R1 --> R2 --> R3 --> R4 end Note["Expand-Contract Rollback
schema never mutated out from under a version, so adjacent versions run against it at once"]:::sidenote DEPLOY -.-> Note ROLL -.-> Note classDef dep fill:#2a9d8f,stroke:#1f7a6f,color:#fff,font-size:13px classDef rb fill:#e9a23b,stroke:#b8791f,color:#222,font-size:13px classDef sidenote fill:#eef2f0,stroke:#9bbdb5,color:#234,font-size:12px linkStyle default stroke:#999,stroke-width:2px