Pick a technology or a problem space.
CoreTrailKitGUIDEDiagnose a Lambda response marshal error caused by a DynamoDB string set, map the returned item to a deliberate JSON contract, and verify it in the official local runtime.
CoreTrailKitGUIDEDiagnose a Boto3 call that gives up before a transient throttle clears, distinguish retries from total attempts, and verify the configured limit with a local HTTP fixture.
CoreTrailKitGUIDEExplain a ConditionalCheckFailedException during a versioned DynamoDB update, preserve the competing write, and reevaluate the operation instead of removing its condition.
CoreTrailKitGUIDEDiagnose a DynamoDB GetItem ValidationException by comparing the full key schema and attribute types, then distinguish an invalid request from an item that is absent.
CoreTrailKitGUIDEHandle one failed SQS record without reporting a whole Lambda batch as failed, configure partial responses deliberately, and retain idempotency for redeliveries.
CoreTrailKitGUIDEInspect a Python Lambda handler’s module name and deployment root, reproduce a misplaced app.py in the official local runtime, and verify the corrected layout.
CoreTrailKitGUIDECompare an S3 bucket’s verified Region with the client and presigned credential scope, and repair URL generation without guessing from the visible hostname.
CoreTrailKitGUIDECompare a presigned S3 upload’s HTTP method and signed Content-Type with the actual request, preserve the URL exactly, and separate signature errors from access policy.
CoreTrailKitGUIDEDiagnose a Boto3 session using unexpected environment credentials, compare implicit and explicit profiles, and verify the intended AWS identity before changing access.
CoreTrailKitGUIDEInvestigate public HTTPS requests that stop working after a Lambda VPC change. Check routes, NAT, DNS, and network policy before increasing timeouts.