Although the monolithic approach has many benefits such as simpler design and a faster communication between components, the inherent complexity of larger applications makes enterprises to think about the microservices approach to follow instead. Microservices approach addresses the complex issues of a monolithic application by splitting the business logic into smaller, standalone modules, allowing development teams to scale up or down, test, develop and deploy them independently. The main purpose of my Thesis was to evaluate the differences between monolithic and microservices based applications, implementing the same functional requirements. I reviewed the virtualization alternatives and selected the Docker container technology to serve as the infrastructure support during my work. I selected the Nginx microservices framework and built a test environment. Starting from an example code I designed a monolithic test application, which implements an online store with selected functionalities. Then I split the code of this application into separate modules according to the principles of microservices and deployed each module in a separate container. Finally, I evaluated the performance of both versions in my testbed and discussed the results.