How I Handle Failures in AWS Step Functions (Without Losing My Mind)
If you’ve ever built workflows with AWS Step Functions, you know things will fail. A Lambda times out, an API throws a 500, network hiccups happen. But the cool part? You don’t need to panic or write complex retry logic.
Step Functions has a built-in retry mechanism, and honestly, it’s one of my favourite features.
Here’s how it works:
You can define a Retry block inside your task. You tell it:
What kind of errors to retry on (ErrorEquals)
How long to wait before retrying (IntervalSeconds)
How many times to retry (MaxAttempts)
Whether to increase the wait time each time (BackoffRate)
For example:
"Retry": [
{
"ErrorEquals": ["Lambda.ServiceException"],
"IntervalSeconds": 2,
"MaxAttempts": 3,
"BackoffRate": 2
}
]
This will retry up to 3 times with exponential backoff: 2s, 4s, 8s.
And if the retries still fail? You can catch the error and gracefully handle it:
"Catch": [
{
"ErrorEquals": ["States.ALL"],
"Next": "HandleFailure"
}
]
No more weird edge-case logic or messy fallbacks in code. Step Functions does the heavy lifting.
If you’re building fault-tolerant workflows (especially for APIs or external services), using retries like this is a no-brainer.