In today’s times, people demand fast, stable, and reliable applications. Therefore, it is essential to choose the right software architecture before implementing functionalities adopted in the project. The monolithic architecture is implemented as a single unit, integrating all functionalities within a single codebase. In contrast, the microservice architecture decomposes the application into several independent services, each responsible for a specific business logic. Key factors such as scalability, fault tolerance, and data consistency are analyzed. Performance metrics, simplicity, flexibility, and the challenges of implementing and maintaining each architecture are gathered and compared. This study offers valuable insights into the practical implications of choosing between monolithic and microservice architectures, especially in the context of applications. It serves as a comprehensive guide for software developers to make informed decisions when designing scalable and reliable systems.