## The symptom
A Bolt WorkflowStep deployed to AWS Lambda (following Slack's bolt-js
serverless deployment docs) has its `execute` function invoked multiple times
per workflow run. In Socket Mode the same code worked perfectly. The duplicate
invocations come from multiple Events API calls visible in the logs, not from
the workflow itself.
## Why
Slack retries the Events API request if your function does not acknowledge
within 3 seconds, so a slow `execute` handler gets invoked again.
## The fix
Acknowledge immediately and do the long work asynchronously. Split the logic
across two functions:
- Function A holds the Workflow Step `execute` handler and only acks, then
asynchronously invokes Function B (e.g. via Lambda async invoke or a Step
Functions state machine).
- Function B does the report generation and posts to Slack.
The reporter confirmed this pattern stops the duplicate executions.
## Watch out
If you never `await complete`, the workflow activity will show "In Progress" in
Slack's UI. Ack fast, but still complete the step when the work finishes.