Cost Savings when Migrating to Micorservices

Quantifying cost savings when migrating from a monolithic architecture to microservices involves several factors:

1. Resource Optimization: Microservices allow you to scale individual components independently, rather than scaling the entire application. This means you can allocate resources more efficiently, potentially reducing overall infrastructure costs. You can measure this by comparing the resource utilization before and after the migration.

2. Compute Cost Reduction: With microservices, you can use cost-optimized compute options for each auto-scaling group. For example, you might use AWS Graviton for workloads suited to ARM-based instances, or leverage Amazon EC2 Spot Instances for stateless components. Compare the compute costs of your monolith with the aggregated costs of your microservices to quantify savings.

3. Development and Testing Efficiency: Microservices enable smaller, focused updates and reduce the need for extensive end-to-end testing. This can lead to faster development cycles and reduced testing costs. Track the time and resources spent on development and testing before and after the migration to quantify these savings.

4. Operational Costs: While microservices can introduce some operational complexity, they also allow for more efficient use of resources. Monitor your operational costs, including personnel time and tools, to understand the impact.

5. Scalability and Performance: Microservices can handle fluctuating business demands more efficiently. Measure the cost of handling peak loads in your monolith versus your microservices architecture.

6. Time-to-Market: Microservices often enable faster innovation and deployment. While this might be harder to quantify directly, you can measure the impact on revenue or customer satisfaction resulting from quicker feature releases.

7. Environmental Impact: If sustainability is a concern, you can use the AWS Customer Carbon Footprint Tool to measure the reduction in carbon emissions resulting from more efficient resource usage.

To effectively quantify these savings, it's crucial to establish baseline metrics for your monolithic application before migration. Then, track the same metrics after implementing microservices. The difference will give you a clear picture of the cost savings achieved through the migration.
Sources
Cost optimization and sustainability - Implementing Microservices on AWS
FSICOST12: Are you saving costs by adopting a set of modern microservice architectures? - Financial Services Industry Lens