====== Step Functions ======

**What it is:** A serverless workflow orchestration service that coordinates multiple AWS services (often multiple Lambda steps).

**What it’s for:**
  * Build reliable multi-step processes (order flow, ETL, approvals).
  * Handle retries, timeouts, error handling, and branching.

**Key ideas:**
  * You define a **state machine** describing steps and transitions.
  * Common patterns:
    * sequential steps
    * parallel steps
    * choice/branching
    * retries/catch

**Exam cues:**
  * “coordinate multiple Lambda functions with retries and error handling” → Step Functions.
  * “workflow with several steps” → Step Functions.

**Hard words:**
  * *workflow* /ˈwɝːkfloʊ/: luồng công việc
  * *orchestration* /ˌɔːrkəˈstreɪʃn/: điều phối
  * *state machine* /steɪt məˈʃiːn/: máy trạng thái
  * *branching* /ˈbræntʃɪŋ/: rẽ nhánh