By default, CloudWatch Log Groups use the Standard log class, which applies higher rates for both ingestion and storage. AWS also offers an Infrequent Access (IA) log class designed for logs that are rarely queried — such as audit trails, debugging output, or compliance records. Many teams assume storage is the dominant cost driver in CloudWatch, but in high-volume environments, ingestion costs can account for the majority of spend. When logs that are infrequently accessed are ingested into the Standard class, it leads to unnecessary costs without impacting observability. The IA log class offers significantly reduced rates for ingestion and storage, making it a better fit for logs used primarily for post-incident review, compliance retention, or ad hoc forensic analysis.

Engineers often enable verbose logging (e.g., debug or trace-level) during development or troubleshooting, then forget to disable it after deployment. This results in elevated log ingestion rates — and therefore costs — even when the detailed logs are no longer needed. Because CloudWatch Logs charges per GB ingested, persistent debug logging in production environments can create silent but material cost increases, particularly for high-throughput services.In environments with multiple teams or loosely governed log group policies, this issue can go undetected for long periods. Identifying and deactivating unnecessary debug-level logging is a low-risk, high-leverage optimization.

CloudWatch log groups often persist long after their usefulness has expired. In some cases, they are associated with applications or resources that are no longer active. In other cases, the systems may still be running, but the log data is no longer being reviewed, analyzed, or used by any team. Regardless of the reason, retaining logs that no one is monitoring or using results in unnecessary storage costs. If log data is not needed for operational visibility, debugging, compliance, or auditing purposes, it should either be deleted or managed with a shorter retention policy.