8Percent's Kiro CLI-based Amazon ECS Modernization Journey

8Percent carried out a modernization project to resolve deployment instability, environment inconsistency, and resource inefficiency issues that had been occurring in its existing Amazon EC2-based infrastructure. This task, which a small team had to carry out while juggling ongoing operations, was accelerated through AI-Driven Modernization Prompt Sets and Kiro CLI.

As the migration strategy, the team adopted a Replatform approach that ported the runtime environment to Amazon ECS Fargate. This secured the following technical benefits.

• Deployment stability: Transitioned from manual package replacement to a CI/CD and Rolling Update system
• Operational efficiency: Eliminated server management overhead and implemented Target Tracking-based auto scaling
• Cost optimization: Moved from 24/7 fixed billing to a task-based pay-as-you-go model, achieving approximately a 76% reduction in monthly operating costs

By reusing the workflow validated on an internal API service for the main API service, the project achieved the verification stage in about 2 weeks despite being a large-scale migration effort.