The selection of a backend architecture is based on the goals and budget set for a particular project. When it is a small project, a monolithic architecture is always preferred. The code is located in one place, and it is easy to design and deploy. But when the size of the application is large, it is not easy to manage.
For big, complex systems, microservices are a stronger choice. This method breaks the application into separate, independent parts. It allows teams to fix or upgrade one feature without stopping the whole system. It is great for scaling but requires more technical effort to manage.
Serverless architecture is perfect for apps that need to handle bursts of traffic without high fixed costs. It removes the need to manage servers entirely. The final decision relies on how much traffic is expected and the skills of the developers. The right choice keeps the app stable now and ready for future expansion.