Monolithic or microservices: which architecture best suits your business?

Imagine your organization’s technology stack. Is it a harmonious symphony — a big, monolithic architecture with components moving and functioning as one? Or is it more of a musical, where singers, the orchestra, and the lighting team each do their own thing — synchronized, yet independent? The choice between a monolithic and microservices architecture is like choosing between a symphony orchestra and a punk band. Both create great music, but they appeal to different crowds, have distinctive structures, and work best in different contexts. 

In a similar vein, both architectural styles have their strengths and weaknesses, and understanding these in the context of your business needs is the first step to deciding which one strikes the right chord for you. So whether you’re more Beethoven No. 7 or Les Miserables (or you’re not sure yet) — this article will help you get to know the pros and cons of both.

What is monolithic architecture?

With monolithic architecture, all the functionality of an app is tightly coupled and managed within a single, unified codebase. Whether it’s the user interface, business logic, or database operations, everything operates under a single operational umbrella.

Advantages

• Simplicity: It’s straightforward to develop, especially for smaller projects. Everything sits inside a single codebase, making it easier to maintain and manage, as well as deploy.

• Consistent data management: With a single, unified database, monolithic architecture makes for an efficient and consistent form of data management.

• Performance: Inter-component communication is more efficient because every component operates under the same process. 

Disadvantages

• Scalability: As an application grows, so does its complexity. Scaling monolithic applications can be a challenge since every change affects the whole system. Plus, you can’t scale independent components independently, which can lead to rising resource consumption. 

• Limited flexibility: Since all functionalities are tightly coupled, making changes or updates to a specific function requires deploying the entire system anew. This means more downtime and slower responses to changing customer demands.

• Single point of failure: With the monolith, a bug in one module can bring down the entire system, because each component’s functionality is dependent on the others. This puts you in a vulnerable spot and could lead to system downtime and unhappy users.

• Difficulty in adopting new tech: The tightly coupled nature of monolithic architecture makes it harder to adopt new tech or frameworks for a specific function without revamping the entire system.

What are microservices?

For those who like straightforward answers — sorry to disappoint! There’s no single definition for what a microservice is. But generally speaking, they are: 

• A collection of services that make up an application;
• Loosely coupled;
• Deployable on their own;
• Easy to maintain;
• Testable;
• Allow for rapid scalability;
• Shaped around business capabilities; and 
• Conducive to continuous delivery.

The main thing to remember with microservices is that they work together, but they are also self-contained pieces that function on their own. 

They’re ideal for fast-growing startups because they’re flexible and allow for fast growth — Netflix, Uber, and Amazon are all fans. 

Advantages

• Scalability: One of the big draws is that you can scale individual components independently, based on demand. If one service sees a surge in demand, you can scale it up without having to do the same to the others.
• Flexibility: Each microservice is built using the technology stack that best suits its requirements. This means more flexibility. 
• Fault isolation: If one service fails, it doesn’t bring the whole lot down. This means you’re more resilient as a business. 
• Easy deployment: You can make changes to one microservice without having to roll it out across the whole app. This means faster innovation and maintenance — good news for startups.
• Parallel development: Microservices make it possible for dev teams to work on different services concurrently, which reduces development time.

Disadvantages

• Complexity: Managing multiple services is more complicated than managing a single application since it requires handling interservice communication, data integrity across services, and more.
• Data management: Each microservice can have its own database, so maintaining consistency across multiple services can be tough.
• Increased resource usage: Microservices usually lead to increased resource usage.
• Testing challenges: Testing is usually more complicated because you need to deal with multiple independent services.
• Distributed system complexity: Microservices architecture is essentially a distributed system, which brings challenges like network latency, message handling, data consistency, and more.

How to choose the right architecture

Choosing microservices or monolithic architecture isn’t just a matter of preference. It’s a strategic decision that will have a significant impact on your business and its scalability and resilience.

Think of it like setting the foundation for a building. If you plan for a small, cozy house, a simple foundation works just fine. But if you plan to build a skyscraper, you’re going to need something more complex. The choice between monolithic and microservices architecture is much the same. 

Consider your goals and the size of your business

In the monolithic world, you’re dealing with one single codebase. The simplicity of this model makes it a great choice for small-to-medium-sized applications. But, as the business grows, so do the challenges. Every change, no matter how small, requires a full redeployment. Scaling particular functions can turn into a headache, with these slowing down your go-to-market speed and impacting your responsiveness.

On the other hand, the microservices approach works like a small, self-contained team that collaborates, but can also work independently. This architecture gives you the flexibility of scaling, updating, and deploying each service independently — great for scalability, but with added complexity. Imagine trying to coordinate different teams spread out around the world, each with its own time zone and function. Managing microservices is a bit like that. 

Why you need to give this some thought

Choosing the right architectural style isn’t just about handling the technology stack, it’s about aligning your tech with your business strategy. Do you need to get to market quickly with a simple yet robust app? A monolithic architecture might be your best bet. Or are you building a large-scale application where you anticipate a need for high scalability and resilience? Then a microservices architecture is probably for you. 

Getting this decision right can be the difference between a smooth, efficient software lifecycle and a tumultuous one riddled with bottlenecks. It can affect everything from your speed of innovation and market responsiveness to your operational costs and revenue growth. So be sure to give it due thought before jumping in! 

How Netflix transitioned from monolith to microservice

The evolution of Netflix is a prime example of the journey from a monolithic architecture to a microservices one. 

Netflix started as a DVD rental service in 1997 before diving into the world of online streaming in 2007. During its DVD-by-mail era, Netflix used a monolithic architecture, which was entirely fitting for its business model at the time. It was simpler, easier to manage, and effectively handled their customer base.

But, as Netflix ventured into the streaming service and expanded globally, the user demand skyrocketed. The company realized that its monolithic architecture would not scale effectively to meet the growing traffic and high availability required for its expanding customer base. Around 2008, Netflix experienced a significant database corruption, resulting in a three-day-long service disruption. This was a turning point for Netflix, pushing them to reevaluate their technology stack and strategy.

What Netflix did next

Netflix recognized the need for a more scalable system. Thus, it decided to break its monolithic system down into hundreds of smaller microservices, each with its own dedicated function. For instance, it had separate microservices for recommendations, user interfaces, movie encoding, and many more. This transition allowed each service to be developed, deployed, and scaled independently.

In this new architecture, even if one microservice were to fail, it wouldn’t put the others at risk. This meant the service would remain available to its users, no matter what — akin to a city’s power grid failing in one district but not affecting the rest of the city. This setup allowed it to deploy updates or new features for one service without needing to redeploy the entire application, dramatically improving the streaming site’s speed and flexibility.

In terms of data storage, Netflix moved from a single centralized database to distributed databases. Each microservice now has its own database, which helps to avoid any single point of failure. Netflix also transitioned to a cloud-based infrastructure on AWS, adding another layer of resilience and scalability to its system.

How to transition from monolith to microservices 

With the right planning and tools, you’ll have a smooth migration and set your business up for success.  

1. Start small

A tried-and-tested method! You can start by decomposing a small part of your monolith that doesn’t directly affect the core business logic. This way, you can gradually adapt to microservices with minimum risk.

2. Set clear boundaries

Each microservice should have a clearly defined responsibility. Use domain-driven design principles to locate the boundaries of your microservices, and make sure each one aligns with a specific business capability.

3. Design for failure

In a distributed system like microservices, failures are a part of life. It’s therefore super important to design your system to handle failures gracefully, using strategies like circuit breakers, fallbacks, and redundancy.

4. Decouple your services

Make sure your services are loosely coupled and can operate by themselves. Avoid direct communication between microservices where possible, and consider using an API gateway or a message broker.

5. Centralize configuration

When you have many microservices, managing the configuration for each service can become complex. Use centralized configuration management tools to handle this as efficiently as possible.

6. Implement service discovery

As the number of your services grows, manually managing service locations becomes infeasible. Implement a service discovery mechanism to automatically manage the locations of your services.

7. Embrace DevOps and CI/CD

Microservices can benefit greatly from a strong DevOps culture and Continuous Integration/Continuous Deployment (CI/CD) practices. These will enable you to manage, test, and deploy each of your services independently.

8. Monitor and log as you go

In a microservices architecture, issues can pop up anywhere. Implement a centralized logging and monitoring solution to easily identify, track, and debug them.

9. Choose the right tools

Research and choose the ones that best fit your needs. These may include container orchestration platforms like Kubernetes, API gateways like Kong or Apigee, and service meshes like Istio or Linkerd. And don’t forget to have diagramming tools at the ready — they make it super easy to map out architecture diagrams with just a few clicks. With Cacoo, kubernetes icons and templates are all there waiting for you, all you need to do is log in, drag and drop, then share your architecture with the team in an instant.

Final thoughts

The choice between a monolithic and a microservices architecture depends on the unique needs and objectives of your project or business, with each approach offering distinct advantages and trade-offs.

A monolithic architecture provides simplicity and ease of development, making it suitable for smaller projects with straightforward requirements and limited scalability needs. On the other hand, a microservices architecture offers modularity and scalability, enabling independent development and deployment of services, making it more suitable for larger, complex projects with evolving needs.

Ultimately, the decision should consider factors such as project complexity, team size, scalability needs, and long-term maintainability, ensuring alignment with your business’s goals for a robust and efficient architecture.