In a figurative sense, monolithic means something like "compact" or "from a single mold". Accordingly, a monolithic software architecture is a complex application that comprises several closely coupled functions. It describes a uniform model for the traditional design of a software program and is being replaced more and more by modular alternatives such as microservices architectures.
Monolithic architecture and its advantages
Monolithic architectures are used to handle multiple related tasks. All included functions of the software are provided in a single code base as a single file.
Such an architecture has the advantage that:
- your company needs only one central point of contact for support,
- the resulting software is self-contained
- it can be easily tested and debugged because it consists of fewer elements and therefore variables,
- it is easy to deploy (just a single file),
- it offers a certain security, since the software consists only of a code basis.
Does monolithic software architecture have disadvantages?
When using monolithic software, you and your team have to face the following challenges or disadvantages:
- The code base of the monolith is very large due to the immense feature set.
- The complexity of the monolithic system makes development and implementation costly and time-consuming.
- Compiling and testing the entire platform may be required even if only a single function is changed.
- Code updates cannot be done independently. Therefore, updates tend to be scheduled infrequently (e.g., quarterly or even less frequently).
- The agile approach collides with the monolithic system, as iterative processes and quick reaction to changing requirements are hardly possible here.
- It is difficult for new team members to understand and familiarize themselves with the code and the workflows due to the high complexity of the code.
- Scalability of individual components is not possible, only scalability of the entire application.
- The wide range of interrelated functions within a monolithic system creates a certain vendor dependency, because: - Monoliths are not designed to interact with other systems.
- This leads to the fact that acquired data can only be used within the monolithic architecture and cannot be analyzed by other software, for example.
- If a new technology or framework is to be used, this is not only possible for part of the application. Instead, developers must rewrite the entire application.
What alternatives are there to monolithic systems?
A modern alternative to monolithic applications is offered by a microservices architecture.
Microservices vs. monolithic software
Microservices are small, independent applications deployed as loosely coupled services. Thus, in contrast to a monolithic software architecture, a microservice architecture consists of several smaller units that are interconnected by application integration. The advantages of microservices over monoliths:
- The individual microservices are easier to develop for the developers from your team (due to smaller feature set).
- Microservices can be optimized more easily and independently (through continuous integration and deployment - CI/CD). Unlike a monolithic version, developers here don't need to rewrite the entire application, but can make modular changes.
- This reduces the risk that one change will lead to unexpected changes in the other elements.
- Faster optimization shortens time-to-market cycles.
- Microservices can be written in any programming language.
- Microservices are able to communicate with other microservices through interfaces (APIs).
- Instead of bundling all functions in a single monolithic platform, your company can choose the best solution for each individual requirement in the form of microservices and connect them via application integration.
- Teams of developers can take responsibility for entire microservices instead of just subtasks in the large monolithic system (such as code writing, testing, maintenance, and operations).
- Choosing the architecture that fits your circumstances and needs
However, before you and your organization completely rule out the use of a monolithic architecture, you should weigh the decision based on your organization's actual needs. For example, a monolithic software architecture may be appropriate in the following cases:
- When modularity and scalability are not needed because the applications are small and simple, don't contain much business logic, and are unlikely to need to change much
- if your company (e.g. as a start-up) currently lacks the resources to implement a complex microservices architecture
Conclusion on monolithic architecture
If you and your company are currently faced with the decision of how to build your software architecture, you should carefully consider what purposes it should serve and what fits your business processes.
For working according to agile methods, a microservices architecture is better suited than a monolithic one, because microservices enable more flexible modular development and improvement and thus iterative processes.