Moving from Monoliths to Microservices: What You Need to Know

When talking about software architecture, businesses often have to choose between sticking with a Monolithic structure or switching to Microservices. While both approaches have their strengths, a growing number of companies are opting for Microservices because of the added flexibility and scalability they offer.

In this post, we’ll walk through the key differences between these two architectures, how each one works, and why it might be time for your business to move from Monoliths to Microservices.

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What’s a Monolith (Monolithic Architecture)?

A Monolithic architecture is the old-school way of building software. With this setup, all parts of the application live in a single codebase. Everything, from the user interface to the backend and the database, is bundled together.

For instance, picture an e-commerce website where users can log in, view products, make purchases, and track their orders. In a Monolithic setup, all these features are handled by the same codebase. It’s one big block, and every function of the app is tightly connected.

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Key Features of Monoliths:

• One codebase handles everything (UI, server, database).
• All functions are bundled together: User login, product catalog, payment processing, and tracking all run from one place.
• Lack of modularity: Any small change requires developers to dive into the entire codebase.

While this approach is easier to start with, it can cause problems as your application grows. For example, any time you need to update or add a new feature, you have to update the whole system, which can be time-consuming and risky.

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Pros of Monolithic Architecture

Monoliths have some advantages, especially for smaller setups:

• Simple to build: With everything in one place, development is more straightforward.
• Easier to deploy: Only one file to manage and deploy.
• Quicker to test: End-to-end testing is faster because everything is tightly integrated.
• Lower latency: With everything in one place, there’s no need for services to communicate over a network.

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Cons of Monolithic Architecture

But Monoliths come with some notable disadvantages as well:

• Large codebase: As your application grows, the code becomes bloated and harder to manage.
• Scaling is tough: Since everything is interconnected, scaling specific parts of your application is challenging.
• Risk of total failure: If one part of the system crashes, the whole app can go down.
• Slow updates: Even minor changes mean working on the entire codebase.
• Not ideal for large teams: With bigger teams, collaboration can become a mess since everyone is working on the same code.

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What is Microservices Architecture?

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In contrast, Microservices architecture breaks the application into smaller, independent services. Each of these services handles a specific function and operates separately. This way, if one part of your app needs an update, you only need to work on that part—without affecting the rest.

In a Microservices setup, each service has its own database, and they communicate with each other using lightweight protocols like APIs. For example, a Microservices e-commerce app would have:

• One service for user login,
• Another for the product catalog,
• A separate one for payment processing,
• And one for order tracking.

Each service operates independently, meaning teams can develop, update, and deploy them separately.

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Pros of Microservices Architecture

Microservices come with a host of benefits, especially for growing or large-scale applications:

• Modular development: You can update or change individual services without affecting the entire system.
• Faster deployment: Only the updated services need to be redeployed, not the whole app.
• Easy to scale: Each service can be scaled independently based on its needs.
• Greater flexibility: Each service can use the best tech stack for its specific job.
• Bug isolation: A bug in one service won’t bring down the entire app.
• Supports large teams: Different teams can work on different services without stepping on each other’s toes.

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Cons of Microservices Architecture

However, Microservices are not without their challenges:

• More complex: Managing multiple services requires more planning and coordination.
• Need for skilled developers: Developing and maintaining Microservices requires expertise.
• Increased network usage: Services have to communicate with each other, which can lead to higher network traffic.
• Security concerns: More points of communication mean more potential vulnerabilities.
• Debugging can be tricky: It’s harder to trace bugs when you have multiple independent services.

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When Should You Move from Monoliths to Microservices?

If your team is growing or if your application is becoming harder to manage due to a large codebase, it’s probably time to think about moving to Microservices. The modularity of Microservices makes it much easier for larger teams to handle different features and services separately.

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Example: Monolith vs. Microservices

With a Monolithic system, if there’s a change needed in one part of the application—let’s say payment processing—the whole app needs to be updated, tested, and redeployed. This increases downtime and the risk of new bugs cropping up elsewhere.

In a Microservices setup, if you need to update the payment service, you can do so without touching other parts like the product catalog or user login. This keeps downtime to a minimum and makes it easier to roll out updates.

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How to Transition from Monoliths to Microservices

Moving from a Monolithic system to a Microservices architecture can be done in a couple of ways:

1. Build a new system based on Microservices
   You can rebuild your entire system from scratch, breaking down each function into a separate service. While this is more effort upfront, it’s the most thorough way to make the switch. However, this can be costly and time-consuming.
   Example: Say you run an employee leave management system. In a Monolithic setup, all features—leave management, payments, user management—are in one codebase. Switching to Microservices would mean breaking each feature into its own service, each with its own database and server.
2. Create separate services that work with your Monolith
   A less disruptive approach is to keep your Monolithic system as is and gradually add new features using Microservices. This allows you to add functionality without rebuilding the entire app.
   Example: If you add a subscription or payment feature to your existing Monolithic app, you could build these new functions as separate services. The old Monolith handles the core functions, while new services handle the add-ons. This approach saves time and reduces costs.

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Final Thoughts

Monolithic architectures are fine for small teams and simpler applications, especially when scalability isn’t a top priority. But as your app and team grow, the limitations of Monoliths become harder to ignore.

On the other hand, Microservices allow larger teams to work more effectively, offer greater flexibility, and make scaling easier. If your business needs better performance and quicker development cycles, making the move to Microservices might be the best option.