Lambda 오케스트레이션을 위한 Step Functions

Chaining many Lambdas by having each call the next gets messy fast — error handling, retries, and visibility become a nightmare.

AWS Step Functions let you orchestrate functions as a clear, visual workflow.

A Step Functions workflow is a state machine defined in JSON using the Amazon States Language (ASL). Each step is a state that does work or makes a decision.

Common state types include:

• Task — run a Lambda or service action
• Choice — branch on conditions
• Parallel — run branches at once
• Map — iterate over a list
• Wait — pause for a time

This workflow runs one Lambda task then ends.

Each Task state can declare Retry and Catch rules, so transient failures are retried and fatal ones route to a cleanup state — no boilerplate in your function code.

A Choice state inspects the workflow data and routes to different next states, letting you build conditional logic visually.

Parallel runs several branches simultaneously and waits for all. Map applies the same steps to every element of an array, with controllable concurrency.

Two workflow types:

• Standard — long-running (up to a year), exactly-once, full audit history
• Express — high-volume, short-lived, cheaper, at-least-once

The console shows a live visual graph of each execution, highlighting which states succeeded, failed, or are running. This makes debugging multi-step flows far easier than scanning logs.

Step Functions can call many AWS services directly — DynamoDB, SQS, SNS, ECS — without a Lambda in between, reducing glue code.

Reach for Step Functions when you have:

• Multi-step business processes
• Long-running workflows
• Complex error handling and retries
• A need to visualize and audit each run

You learned Lambda orchestration:

• State machines define workflows in ASL
• Choice, Parallel, Map control flow
• Retry and Catch handle errors declaratively
• Standard vs Express match cost to workload

Step Functions turn tangled Lambda chains into reliable, visible workflows.