Lab 4C — Step Functions capstone

15 timed scenario questions (~24 min, ~96 sec each). Reinforces night-32-stepfunctions-capstone.md and gsa-stepfunctions-map.md. Answer without peeking at night-32-quiz-answers.json first.

1. 1.Global Ski Atlas needs a monthly workflow: run Iceland Fargate for up to two hours, enqueue completion to SQS, invoke a stats Lambda, and route failures to SNS with different retry counts per step. Which service is the best orchestration fit?

   A.Step Functions Standard workflow with per-step Retry, Catch, and sync integrationsB.EventBridge schedule using five separate rules with no shared execution historyC.SQS FIFO queue with a single consumer handling every pipeline stage inlineD.Kinesis Data Firehose delivery stream writing each stage output straight to S3

2. 2.The capstone uses `arn:aws:states:::ecs:runTask.sync` for Iceland. What does the `.sync` suffix mean for the state machine?

   A.ECS pushes a callback token as soon as the container process starts runningB.Step Functions waits until the ECS task reaches STOPPED before advancingC.The Fargate task runs synchronously inside the Lambda execution environmentD.EventBridge forwards ECS state-change events without the workflow waiting

3. 3.A Step Functions `RunTask` state fails with `ECS.AmazonECSException` after two retries. The ASL has a `Catch` to `PublishFailureAlert` (SNS). What happens next?

   A.The execution ends successfully because the Retry block already completedB.SQS automatically moves an unseen message into the configured dead-letter queueC.The Catch state runs and publishes a failure alert to the Night 14 SNS topicD.EventBridge disables the monthly schedule rule after the second failed retry

4. 4.Night 32 deploys a new EventBridge rule `saa-study-gsa-iceland-monthly-sfn` targeting the state machine. The legacy `saa-study-gsa-iceland-monthly` rule still targets ECS directly. What is the operational risk?

   A.SNS topic subscriptions for Iceland alerts are deleted without warningB.Step Functions Express execution history is truncated after five minutesC.SQS FIFO message ordering for wiki traffic is violated by the new ruleD.Two Iceland Fargate tasks may start on the same monthly schedule window

5. 5.Which IAM permission must the Step Functions execution role have for `ecs:RunTask` on the Iceland task definition?

   A.iam:PassRole for the ECS execution role and the task role used by RunTaskB.s3:PutObject on the pipeline output bucket as the only required permissionC.lambda:InvokeFunction on the stats uploader without any PassRole grantsD.events:PutTargets on the legacy monthly rule to replace the ECS target

6. 6.An exam scenario needs sub-minute fan-out of thousands of short payment authorizations with optional discarded execution history. Which Step Functions type fits?

   A.Standard — retain a full durable audit trail for every authorization attemptB.Express — high volume, short duration, lower per-execution overheadC.Standard with `.waitForTaskToken` blocking on every authorization stepD.SQS standard queue alone with no workflow orchestration service involved

7. 7.After `RunIcelandTask` succeeds, the capstone sends a message to `saa-study-gsa-iceland-completion` via `sqs:sendMessage`. Why keep SQS instead of only synchronous Lambda invoke?

   A.SQS is mandatory because Step Functions cannot invoke Lambda Task statesB.SNS fan-out is always slower than SQS for every completion notification pathC.Durable buffer plus the existing Night 17 event source mapping / replay pathD.SQS is the only service that can express monthly cron schedules for Iceland

8. 8.In the Night 32 ASL, `InvokeStatsUploader` has Retry on `Lambda.ServiceException` but Catch on `States.ALL` to SNS. Lambda returns a handled error in the payload with HTTP 200. What happens?

   A.Catch runs immediately because the function returned a JSON error objectB.Retry runs because Lambda.ServiceException was not thrown by the runtimeC.The execution pauses until an SQS DLQ redrive restarts the Task stateD.The Task state succeeds and the workflow continues toward PublishSuccess

9. 9.How does AWS primarily bill Step Functions Standard workflows?

   A.Per state transition (with duration charges for some long-running integrations)B.Per ECS cluster hour regardless of how many state machine executions runC.Per SNS email delivery only when a Publish state appears in the ASLD.Flat monthly fee per state machine definition regardless of transition count

10. 10.Night 28 used EventBridge `saa-study-gsa-iceland-success-to-sqs` on ECS Task State Change. Night 32 Step Functions also `sendMessage`s to the same queue. What should you do to avoid duplicate completion messages?

    A.Delete the SQS queue and recreate it with a new name and empty backlogB.Disable the legacy success EventBridge rule or remove its target when SFN owns enqueueC.Switch the queue to FIFO and rely only on content-based deduplicationD.Replace the SNS failure topic with Kinesis Data Streams for completion events

11. 11.A human approval gate is required mid-workflow before publishing ski stats to production Aurora. Which Step Functions pattern applies?

    A.Express workflow that only runs `ecs:runTask` without waiting for operatorsB.SQS long polling configured directly inside the state machine definition JSONC.Task state with `.waitForTaskToken` until an operator calls `SendTaskSuccess`D.CloudWatch alarm action on FailedInvocations used as the approval signal

12. 12.The Iceland container exits with code 1 after starting. With `runTask.sync`, how should the capstone surface failure to operators?

    A.CloudWatch FailedInvocations on the schedule rule — the container already ranB.SQS redrive policy alone sends email without any Catch configurationC.Step Functions Express discards the error and marks the execution succeededD.The RunTask state fails; Catch routes the failure to an SNS publish state

13. 13.Which integration ARN publishes a success notification to the existing `saa-study-gsa-iceland-alerts` topic at the end of a happy path?

    A.arn:aws:states:::sns:publish for the PublishSuccess notification stateB.arn:aws:states:::sqs:sendMessage for the completion queue enqueue stepC.arn:aws:states:::ecs:runTask for starting the Iceland Fargate containerD.arn:aws:states:::events:putEvents for writing a custom EventBridge bus event

14. 14.Why is Step Functions Standard (not Express) correct for the Iceland capstone?

    A.Express workflows cannot integrate with SNS publish Task states at allB.Express max duration is five minutes — Iceland may run about two hoursC.Standard workflows cannot define Catch blocks for failed Task statesD.Express requires a FIFO SQS queue as the mandatory first state in ASL

15. 15.A teammate suggests replacing the entire Night 32 state machine with a single EventBridge cron → `ecs:RunTask` like Night 12. What capability would they lose?

    A.Ability to place Fargate tasks in private subnets with no public IPB.Permission to write pipeline GeoParquet output objects into the S3 bucketC.Per-step Retry/Catch, sync wait for STOPPED, and a visible multi-step graphD.Use of IAM task and execution roles on the ECS Fargate task definition