Microservices vs. Monolithic Architecture: What Is the Difference?

Microservices and monolithic architecture refer to two types of software development models. Monolithic architecture is the traditional approach to development, while microservices architecture is a more recent approach. The fundamental difference between the two is that monolithic architecture uses one code base connected to a single database with a server-side application that produces the client-side interface. Microservice architecture, however, splits up the code base into a distributed architecture that uses application programming interfaces (APIs) to communicate. 

It may help you to think of software architecture as a building project. With a monolithic approach, you build one large building that houses every person. It’s efficient to build this way, but to include more people, you would need to scale the entire building, which would be complex and costly. However, with a microservices approach, you would build smaller structures across a larger area but keep each connected through a single community. This approach distributes the building, and while it’s not as efficient, it is a far more effective way to add structures as the community grows. 

Analyze both developmental architectures, including their use cases, advantages, and drawbacks, as you consider which one of the two methodologies is best for your organization or DevOps team. 

What are microservices?

Microservices architecture, or just microservices, is an application development approach that breaks down a piece of software into a collection of independent components. It enables different parts of the team to work independently on various aspects of the application without hindering another software developer’s work. Each function of the application becomes one service, and each service communicates with the others through APIs. 

Microservices are cloud-native applications that use a series of components that work with any cloud environment. Containers package microservices into the components that a cloud application deploys, allowing for continuous integration/continuous development (CI/CD) of applications. Popular containerization platforms include Docker and Kubernetes, which help you actually utilize, orchestrate, and deploy microservices. 

What is an example of a microservice?

A popular example of microservices architecture is an e-commerce platform. E-commerce platforms have many components, including a search function, customer accounts, a shopping cart, inventory management, and checkout. By breaking each element into its own microservice, you can quickly deploy updates, new features, and customer personalization. Bringing each microservice together makes up the microservices architecture, and thus the entire e-commerce application. 

What can you use microservices for?

If you want to break up any application that utilizes a monolithic architecture or build applications faster, microservices can help. Some ways that you can implement microservices include:

• Websites: Managing a massive monolithic website is cumbersome. Since microservices break the website into smaller components, you can use the cloud as a host instead of traditional server architecture. 

• Streaming services: Streaming services can utilize microservices to manage image and video content and serve it on the web or through a mobile application. 

• Data processing: With microservices, applications can manage a higher volume of data processing requests at one time.

Is Netflix monolithic or microservices?

Netflix began as a monolithic application that migrated to a cloud-based, microservices architecture in 2008 after experiencing a database corruption, which resulted in three days of downtime. This transition allowed them to have reliable and scalable DevOps through Amazon Web Services (AWS), completing the transition for front-end and back-end in 2015. [1] This example demonstrates how many companies begin using monolithic architecture and then transition to microservices as they scale. 

What is monolithic architecture?

The basic explanation of monolith architecture is that a single, centralized code base manages all application functions. Monolithic architecture in software traces its origins back to the 20th century through the IBM mainframe computers of the 1960s and 70s [2]. Today, software developers still utilize monolithic architecture for its consistency throughout IT development. 

Monolithic architecture has three main components to it:

• Client-side: The client-side user interface (UI) is how you (the application user) actually interact with the application on your computer or device. It also dictates what you see and how you use the app. 

• Database: Monolithic architectures use relational databases connected to the application. 

• Server-side: The server-side manages application resource usage like memory, CPU, and storage space. 

Like the name implies, monolithic architecture is a unified, tightly coupled system in which many different components of the application depend on one another. The application is large and self-contained, and if one part needs new code or an update, other parts of the application often have to be rewritten. 

Monolithic architecture example

Since monolithic architecture historically came before microservices, many companies have built their applications upon monolithic architecture and then transitioned to microservices when it suited them, including Netflix, Uber, and Facebook. WordPress has stayed a monolithic application, as has the Linux kernel OS. 

Consider the e-commerce example from above to demonstrate how a monolithic architecture works compared to microservices. If it were to function as a monolithic architecture, search function, customer accounts, a shopping cart, inventory management, and checkout would all be a part of one application. This may work well for a smaller e-commerce platform, but it can become hard to manage once you want to roll out new features and updates frequently. 

What is monolithic architecture used for?

Monolithic architectures are traditional ways for you to begin building an application. This makes monolithic architectures particularly useful for:

• Start-up companies: Monolithic architecture is simpler for start-up companies because they can release their applications without the investment required for microservices. 

• Basic applications: An application only needs to be as complex as it needs to be, so for the simplicity of one code base, basic applications or prototypes may be all your project needs. 

Is Kubernetes monolithic or microservices?

Kubernetes is not a monolithic service but a container orchestration platform that allows developers to make use of microservices. It provides resilient workflows for container management, helping you deploy a new container if one fails, drastically reducing application downtime. 

Microservices vs. monolithic architecture: Pros and cons

The long and short of it is that monolithic architecture uses one code base and one database in developing an application, while microservices break each component of the application into multiple code bases and databases that communicate via APIs. 

Review monolithic vs. microservices pros and cons in the table below:

Should you choose microservices or monolithic architecture?

When choosing between microservices and monolithic architecture, one essential aspect to consider is the current size of your organization and how you plan to scale in the future. It’s important to remember that massively successful companies like Netflix, Uber, and Spotify scaled to microservices when their business needs required them to. At the core, you need a solid application, and implementing microservices too early in development could introduce unwanted complexity into the development process. 

Some factors you may want to consider when deciding between the two:

• If your application is small, a single code base may work just as well as microservices. However, with larger applications, the time spent developing microservices can reduce complexity in the long term. 

• Developing microservices means that your team must integrate cloud services, APIs, containerization, and other DevOps experiences that go beyond simply creating an application. 

• One of the advantages of a monolithic architecture is that its development and deployment only require using a single server for the code base and database. Creating microservices requires investment in additional infrastructure, workflows, and skills. 

Learn about software development on Coursera

Monolithic and microservices software development architecture both have their place within application development; choosing one over the other depends on a myriad of factors. Continue learning about various architectures and build in-demand skills on Coursera. For example, you might consider the IBM Full Stack Software Developer Professional Certificate for an opportunity to learn how to develop, deploy, and scale applications, or the IBM DevOps and Software Engineering Professional Certificate, which offers a chance to build applications using microservices while gaining a solid foundation in DevOps and Agile methodologies.