Optimizing Microservices Architecture Using Multi-Criteria Decision Making (MCDM): A Case Study Of PayPal REST API

In the digital transformation era, businesses are increasingly adopting microservices architecture to enhance their software systems' flexibility, scalability, and maintainability. Optimization is needed to achieve these goals. Microservices architecture optimization was applied to a study case of PayPal REST API microservices. There are five architectures include one actual architecture and four developed from the actual architecture. These architectures are based on optimizing criteria such as granularity, complexity, and cohesion. The architecture evaluation uses Service Granularity Metrics (SGM), Number of Operations (NOO), and Lack of Cohesion Metric (LOCM) in various weights. Multi- Objective Optimization based on Ratio Analysis (MOORA) and Complex Proportional Assessment (COPRAS) models are used to determine the best architecture. Almost every architecture alternative suit a specific level of granularity, but alternative 4 has balanced results for each criterion. The evaluations demonstrate that the actual architecture maintains high granularity and showing superior performance in managing operational complexity effectively when assessed against alternative architectures.