Any documentation about `Lambda:ExecutionTimeoutException`?

Today I encountered a `Lambda:ExecutionTimeoutException` in my mutation `ResponseFunctionEvaluation` (within a pipeline) 🤔

When logging `context.error`, I got the following output:

```js
{
unhandledErrorType : null,
message : "Execution timed out.",
type : "Lambda:ExecutionTimeoutException"
}
```

Usually when my Lambda function times out I get:

```js
{
unhandledErrorType : "Sandbox.Timedout",
message : "..."
}
```

### Questions

1. What's the difference between [`Sandbox.Timedout`](https://docs.aws.amazon.com/lambda/latest/dg/troubleshooting-invocation.html#troubleshooting-timeouts) and `Lambda:ExecutionTimeoutException`?
2. Is `Lambda:ExecutionTimeoutException` handling the hard 30 seconds AppSync timeout on mutation?
3. My Lambda has 10 seconds timeout, so what could have happened?

Any official documentation or insights on this would be appreciated! Google search on "_Lambda:ExecutionTimeoutException_" gives nothing: https://www.google.com/search?q=%22Lambda%3AExecutionTimeoutException%22

Start with the mutation ResponseFunctionEvaluation and the logged context.error payload, then compare it with the linked AWS Lambda timeout documentation and the reported 30-second AppSync mutation limit. Done means documenting the distinction between Sandbox.Timedout and Lambda:ExecutionTimeoutException and explaining which timeout conditions can produce each error.

Written by the indexing model from the issue text.