Task timed out after X seconds means your Lambda function didn’t finish within its configured timeout (default 3 seconds, max 15 minutes).

What causes this error

1. Timeout too short — default is 3 seconds, which is too short for most real work
2. Slow downstream service — database, API, or S3 call taking too long
3. Cold start — first invocation takes longer due to initialization
4. Infinite loop or deadlock — code never completes

Fix 1: Increase the timeout

In serverless.yml, CloudFormation, or the AWS Console:

functions:
  myFunction:
    timeout: 30  # seconds (max 900 for 15 min)

Fix 2: Optimize cold starts

• Use smaller deployment packages
• Use provisioned concurrency for critical functions
• Avoid heavy imports at the top level — lazy-load instead

Fix 3: Add timeouts to downstream calls

// Don't let an external API hang your Lambda
const response = await fetch(url, { signal: AbortSignal.timeout(5000) });

Fix 4: Check for connection issues

Lambda functions in a VPC need a NAT Gateway to reach the internet. Without it, external API calls hang until timeout.