Resilience Patterns — Simple

Problem statement (interviewer prompt)

Walk through the resilience toolkit (timeouts, retries with jitter, circuit breakers, bulkheads, hedged requests, backpressure, graceful degradation). For a checkout flow with five downstream calls, explain which patterns you'd apply at each call and why.

flowchart LR
  C[Caller]
  TO[Timeout]
  RT[Retry + backoff]
  CB[Circuit Breaker]
  BH[Bulkhead<br/>isolated pool]
  FB[Fallback]
  S[Downstream]
  C --> TO --> RT --> CB --> BH --> S
  CB -. open .-> FB

    classDef client fill:#dbeafe,stroke:#1e40af,stroke-width:1px,color:#0f172a;
    classDef edge fill:#cffafe,stroke:#0e7490,stroke-width:1px,color:#0f172a;
    classDef service fill:#fef3c7,stroke:#92400e,stroke-width:1px,color:#0f172a;
    classDef datastore fill:#fee2e2,stroke:#991b1b,stroke-width:1px,color:#0f172a;
    classDef cache fill:#fed7aa,stroke:#9a3412,stroke-width:1px,color:#0f172a;
    classDef queue fill:#ede9fe,stroke:#5b21b6,stroke-width:1px,color:#0f172a;
    classDef compute fill:#d1fae5,stroke:#065f46,stroke-width:1px,color:#0f172a;
    classDef storage fill:#e5e7eb,stroke:#374151,stroke-width:1px,color:#0f172a;
    classDef external fill:#fce7f3,stroke:#9d174d,stroke-width:1px,color:#0f172a;
    classDef obs fill:#f3e8ff,stroke:#6b21a8,stroke-width:1px,color:#0f172a;
    class C,TO,RT,CB,BH,FB,S service;