Monolith vs. Microservice: Which is the better Fit?

Developers are often faced with the choice between modular monoliths and microservices. This blog post compares the two approaches and helps you to find the best solution for your project.


In the world of software development, the topic of system architecture is of crucial importance. The discussion about modular monoliths and microservices is particularly intense. But which type of architecture is better? The answer is complex and depends heavily on the respective use case.

The Fascination for Microservices

Microservices are ubiquitous in the IT industry and are often seen as the modern standard for scalable and robust software solutions. Thanks to technologies such as cloud solutions and containerization, especially through Docker and Kubernetes, microservices have gained popularity. This architecture promises better scalability and flexibility by dividing large applications into smaller, independently manageable services. However, microservices also come with challenges:
- Complex service communication and API management
- Increased resource requirements
- Difficulties with debugging
- Potentially high costs

Many companies implement microservices without fully understanding the challenges involved, which can lead to inefficient and expensive solutions.

The modular Monolith as an Alternative

In contrast to this is the modular monolith, an architecture that offers advantages for small to medium-sized projects in particular. A modular monolith consists of independent modules, each of which contains everything necessary for its functionality and has clearly defined interfaces. This structure offers several advantages:
- Reduced complexity compared to microservices
- Easier refactoring and maintenance
- Lower operating costs

Especially when it comes to the development of simple CRUD systems or MVPs, a modular monolith often proves to be sufficient. Modularity also makes it possible to convert individual modules into microservices if required as soon as the system and requirements grow.

Domain-Driven Design and modular Monoliths

The integration of Domain-Driven Design (DDD) into a modular monolith can further improve its structure. DDD focuses on developing software around the core processes and rules of a specific business area. In a modular monolith, each module can correspond to a so-called "bounded context", which clearly structures the business logic and facilitates future extensions.

Conclusion

Although microservices have their place in large-scale projects such as Netflix or Shopify, a modular monolith is often the better choice for most small to medium-sized companies. This architecture offers a balanced combination of modularity, simpler management and cost efficiency. The key is that each company chooses the right architecture form based on its specific requirements and resources.