#sqs

Cloud & Infrastructure Bug Report

Users randomly could not log in: our Cognito post-authentication Lambda exceeded the 5-second limit

Tomás Herrera · Jul 23, 2026 · 7 min read

A few percent of logins failed with a generic error after we added a Cognito post-authentication trigger that recorded login events in our database. The Lambda ran in a VPC, opened a database connection on cold start, and sometimes exceeded Cognito's 5-second trigger timeout. How we moved the work off the login path.

Cloud & Infrastructure Bug Report

EventBridge rule matched but the SQS queue in another account stayed empty: queue and KMS policies

Tomás Herrera · May 29, 2026 · 7 min read

Order events from our platform account were supposed to reach an SQS queue owned by the analytics account. The rule showed matches, the queue showed nothing, and no error appeared anywhere obvious. Causes: a queue policy without the rule ARN, a KMS key policy that denied EventBridge, and no DLQ to tell us.

DevOps & CI/CD Bug Report

Correlation ID in API logs but missing in SQS consumers: propagating it with Lambda Powertools

Elena Kovač · Oct 20, 2025 · 8 min read

Our API Lambda logs carried a correlation_id from API Gateway, but the SQS consumer logs had none, so we could not follow a request across the queue. Powertools only reads correlation IDs from the event it is given. How we passed the ID as a message attribute and injected it per record in the consumer.

Cloud & Infrastructure Bug Report

ECS scale-in killed SQS workers mid-job and jobs ran twice: task scale-in protection

Tomás Herrera · Jun 7, 2025 · 7 min read

Our ECS Fargate workers scaled on SQS queue depth. After each burst, scale-in stopped tasks in the middle of 10-minute PDF jobs; messages reappeared and the jobs ran again, sending customers duplicate documents. How we fixed it with task scale-in protection, SIGTERM handling and a visibility timeout that fits the work.

DevOps & CI/CD Bug Report

Terraform count index shift: removing one list item planned to replace half our queues

John Nguyen · Feb 17, 2025 · 9 min read

We deleted one queue name from a Terraform list and the plan wanted to destroy and recreate every queue after it. count addresses resources by position; we moved to for_each with moved blocks and changed nothing in AWS.

Cloud & Infrastructure Bug Report

SNS to SQS fan-out delivered our JSON as an escaped string inside an envelope: raw message delivery

Tomás Herrera · Dec 8, 2024 · 8 min read

We put SNS in front of an SQS queue to fan out order events, and the consumer Lambda started failing with KeyError: 'orderId'. Each SQS message body was now an SNS envelope with our event as an escaped JSON string in Message. How raw message delivery fixes it, and what changes for filtering and attributes.