What is a monolithic application?

Overview

In software engineering, a monolithic application is a single-tiered software application. It consists of 3 layers:

• User interface layer 
• Application layer 
• Data layer

The UI layer is the client-side of the application. It usually consists of various HTML, CSS, and JavaScript pages. The application layer is the server-side of the application where we write all the logic. The data layers consist of database objects. The application is deployed as a single unit regardless of the technologies, components, and tools.

Why should we choose monolithic architecture?

Using monolithic architecture has several advantages:

Easy to develop and deploy

Monolithic applications require just one directory, and everything is usually in one place, making it easier and straightforward to develop. The deployment is also quite simple because there's usually one file/directory instead of multiple deployments.

Easy to test and debug

It's challenging to test and debug multiple components. A monolithic application allows us to implement end-to-end testing, making it easier to fix the bugs.

Note: End-to-end (E2E) testing is a type of testing that allows us to test our workflow from the beginning to the end. 

Looking at the various advantages of monolithic architecture, why do people still prefer Microservices. Let’s take a quick look at what Microservices architecture is? 

Microservices architecture

In monolithic, we build a single unit application whereas, in microservices, we build our application by splitting it into interconnected services, each of which has separate databases. The main issue with monolithic applications is scalability and maintenance, which increases with bigger and more complex projects.

Microservices tackle this problem in a way that it performs more frequent deployments, which also saves time and resources. Moreover, microservices make it more manageable as each microservice is small and understandable to developers.

However, the complexity of the level is much higher in microservices compared to monolithic. If it’s not done correctly, it can lead to a loss of resources and time.

Here is a comparison between monolithic and microservices:

Wrap up

Choosing the right architecture is vital for every project. This article covers what a monolithic application is and when we should opt for it. A similar architecture, Microservices, was discussed to provide us with a broader picture when we're choosing between the two.