###### Abstract
Although various solutions already exist, the process of migrating from monolithic to microservices architectures still lacks accuracy measurement. Moreover, a brief literature review uncovered some differences in the performance of these architectures [6]. Based on the given issues, this study focuses primarily on a compilation of results from established research about the evaluation of both architectures. Secondly, it focuses on determining the performance and the relationship between different variables such as CPU, memory consumption, network performance, disk operations, and restrictions such as development time, integration, and migration effort of an application that proceeds from a monolithic structure towards one of the microservices. Indeed, this is complementary to [7] and an expansion of our previous work published in [8], where the data from those measurements will let us present a complete critical analysis, and new knowledge related to the evolution from Monolithic to Microservices architectures, including their performance, and development complexity. We also analyze a complete state-of-the-art to assume a critical position regarding what remains to be performed in the given context. Furthermore, we evaluated two different scenarios, of which one comprises an application based on a monolithic architecture that works on a virtual server with KVM. The other scenario deploys the same application, based on a microservice architecture that runs in containers. Both cases were exposed to stress tests of similar characteristics and with the same hardware resources. For its validation, we applied the non-parametric regression mathematical model to explain the dependency relationship between the known performance variables. The results and the corresponding comparisons allowed a decision that directly focused on efficient resources management and software operation efficiency. Among the main contributions of the current study, we can consider: (1) The construction of a critical analysis of research production about the comparison of performance between monolithic versus microservices architecture. (2) A critical review of variables and constraints that impact the performance of architectures migration and a critical analysis of the evolution from monolithic to microservices architectures in terms of their applications, efficiency, and development complexity. (3) An evaluation of response times and resource consumption of microservices architecture; this would justify adopting such architecture based on its modularity as a new business technology or in applications of new technological trends. (4) A quantitative comparison of monolithic versus microservices architectures through the mathematical non-parametricregression model that explains the dependency relationship between the selected variables, this will be required to decide when to use such architecture. The remainder of this article is organized as follows. Section 2 discusses the state-of-the-art, while Section 3 presents the theoretical framework. Section 4 describes the experimental design, including an explanation of the mathematical model applied to validate the preliminary results. Section 5 details the evaluation process of both architectures as well as their findings and includes a discussion. Finally, Section 6 presents the conclusions and future work lines.