ERP System Migration to AWS Cloud via Serverless Infrastructure and Terraform

To reduce operational costs, the existing IaaS-based AWS architecture should be migrated to a serverless architecture. The new setup should be built using Terraform, following the principles of Infrastructure as Code.

Challenge

An analysis of the current state of an existing ERP system revealed that API usage was relatively low and concentrated within specific time windows—primarily when employees logged their working hours. Outside of regular business hours, such as evenings and weekends, the system saw minimal activity. However, maintaining a continuously running server resulted in ongoing infrastructure costs that were disproportionate to actual usage.

To reduce the costs and improve scalability and maintainability, the ERP system was migrated to a serverless architecture using AWS Lambda functions. This approach ensures that computing resources are only consumed when needed, eliminating idle time and reducing operational expenses.

Key Challenges During the Migration

One of the main challenges was replacing the existing cron jobs. These scheduled tasks—such as daily reminders prompting employees to log their hours—previously relied on a server that was always online. With the shift to a serverless model, this assumption no longer held.

Infrastructure as Code with Terraform

To bring the benefits of modern software development practices—such as version control, repeatability, and transparency—into the cloud infrastructure, Terraform was adopted as the Infrastructure-as-Code (IaC) tool of choice. This decision brought several advantages:

• Versioning: Infrastructure changes are tracked and can be rolled back if necessary.
• Documentation: The current state of the infrastructure is clearly defined and accessible to all developers.
• Stability: Manual and ad-hoc changes are avoided, reducing the risk of misconfigurations.
• Automation: Provisioning and updating resources becomes consistent and efficient.

Conclusion

Migrating the ERP system to a serverless architecture not only significantly reduced operational costs but also laid the foundation for a modern, scalable, and maintainable infrastructure. By leveraging AWS Lambda, EventBridge, and Terraform, the system now aligns with cloud-native best practices and is better equipped to adapt to future demands.