• Check the API gateway error rate and identify which specific endpoints are failing (4xx/5xx breakdown).
• Review application logs for stack traces, database connection errors, or timeout patterns in the last 30 minutes.
• Scale up the affected service horizontally if CPU or memory is the bottleneck — add instances immediately.
• Check all downstream dependencies (database, cache, third-party APIs) for health issues.
• Roll back the most recent deployment if the incident started shortly after a release.
• Notify affected clients/stakeholders with an estimated resolution time and update status page.