Monolith vs Microservices: How To Choose The Right Architecture

Without a doubt, today, the term microservices is trending both in on-site and outsourced software product development—according to the independent web resource Research and Markets, the microservices market is expected to grow to $10.86 billion in 2027 at a CAGR of 19.6%. At the same time, it’s hardly possible to consider this type of architecture “one-size-fits-all” for any enterprise evolving in the digital plane. Below, we’ll explain why a dedicated development team may refuse this architecture style and highlight the key differences between monolithic and microservices architectures.

Evolution of Software Architecture

Initially, all applications were created as monolithic architecture systems—they consisted of three main components: the client side user interface, the database, and the server side. In such applications, all business logic was executed in a single process, which led to the fact that any changes made to the program code required a rebuild of the entire project. This means that if the project was regularly updated, it became increasingly difficult to maintain a convenient structure for it since each of the modules gradually acquired more and more new dependencies.

These inconveniences gave rise to microservices: an architectural style based on building applications as a set of services. Each of these services could be deployed and scaled independently of the others and, moreover, reused in other projects. This flexibility has opened up new scaling opportunities, making it much easier for developers to complete their tasks.

In fact, the concept of microservices has been discussed in the global developer community since the mid-2000s. Less than a decade later, digital giants such as Amazon, Netflix, and Twitter announced the introduction of microservices as part of their own software developments. You can also check this article to better understand this concept on a specific microservices architecture example.

At the same time, microservices are still subject to criticism to this day: developers often have to make a lot of effort to level out network delays caused by modules’ interactions with each other, as well as agree on message formats due to the lack of data standardization.

However, with the right approach, this style of software architecture completely pays off. Below, we will look at the concept of monolithic architecture and microservices in more detail and also highlight its key advantages and disadvantages.

What Are Microservices?

Microservices are self-contained software modules that are designed to perform one single function. Developing applications in this architectural style involves following certain code organization rules, which should include automation of development and testing, as well as reduction of legacy code.

In fact, microservices-based applications are created as a collection of small, independent services, each of which runs its own process and communicates with the others through API, using standard communication protocols like HTTP. Unlike the monolithic architecture architecture, dependencies between microservices are peer-to-peer, which allows them to be created in different languages using different data storage technologies. Overall, this approach to software development allows project teams to create flexible solutions in which they can deploy or deactivate features in a matter of minutes.

Advantages of Microservices

Now, let’s look at the main benefits of microservices-based architecture in our microservices vs monolithic architecture comparison.

Scalability

When implementing this approach, each microservice has its own dedicated resources that can scale dynamically, which, in the long run, prevents software failures. In particular, this is typical for popular DevOps orchestration tools like Kubernetes. Microservices also make it easier to add new functions, eliminating downtime since there is no need to deactivate the entire system.

Fault Tolerance

Microservice applications are more fault-tolerant than monolithic ones since, in this case, the failure of one feature does not mean the failure of the entire system—only those associated with this service will not work. However, such situations can also be prevented by implementing the isolation of services from each other.

Less Dependencies

Microservices imply peer-to-peer rather than hierarchical dependence of services on each other, minimizing class inheritance. This means that updates to individual services will not lead to the collapse of the entire system if new errors occur in the program code.

Tech-agnosticism

When choosing microservices, you get unlimited opportunities to implement any technology and use any tools and programming languages. This means that, in theory, you could even hire several separate development teams, each working independently of each other. This lack of connection to a technology stack allows product owners to use the best that the modern software development industry offers to implement the intended functionality.

Great Opportunities to Experiment

Sometimes the outdated nature of some software solutions makes it impossible to integrate them with new software. In turn, if you choose a microservice approach for your custom product, this allows you not to reinvent the wheel but to use what has already been created (even if it is legacy), connecting it to a microservice specially created for this purpose.

Disadvantages of Microservices

For the objectivity of our microservices vs monolithic architecture review, below, we will consider the main disadvantages of microservices. However, note that with the right approach on the part of developers, most of them can be prevented.

High Complexity of Communication

For a large application, a microservices architecture is more complex compared to a monolithic architecture in terms of a larger number of modular components, each of which has its own database. This can lead to data consistency and integrity issues, as well as unacceptable time delays.

More Resources for Maintenance

Microservice solutions require quite a lot of computing resources, which is explained by the fact that each service runs in its own environment. This often results in increased memory and CPU usage. Therefore, to achieve cost-effectiveness, your outsourcing web development team will need to think more about how to implement dynamic resource allocation.

Difficulties in Global Testing and Debugging

Project testing can be complex due to the large number of services and dependencies between them. This means you may need a new, well-thought-out testing strategy. Moreover, if several teams are working on your project simultaneously, this can further complicate global testing and debugging procedures.

The Need for Automated Deployments

Deploying microservices-based applications involves deploying many independent services, which can be more complex than in the case of a single monolithic application. In this regard, the introduction of tools for automated deployment is inevitable, which can provoke new difficulties for your in-house IT department.

Increased Costs

Finally, it’s important to understand that creating systems based on microservices is a comprehensive approach that also involves the implementation of DevOps practices, tools, and more costs. If you understand that this is not what your company needs now, microservices are probably not the best option.

What is Monolithic Architecture?

Building an application based on a monolithic architecture implies resorting to a traditional software development model involving the creation of a single code base to perform all functions assigned to the project. All software components of a monolithic system are interdependent due to the use of built-in data exchange mechanisms within the system. As a result, updates, integrations with other services, and other modifications to such systems are limited and often take a lot of time, because even small changes affect large parts of the code base.

Along with this, a monolithic model can be convenient in the early stages of a project (for example, when developing a minimum viable product) since it’s easier to manage the code base, and the deployment procedure itself does not require any extra measures.

Advantages of a Monolithic Architecture

Now it’s time to discuss the benefits of monolithic systems in our microservices vs monolithic architecture comparison.

Helpful for Projects with Unclear Requirements

If your project still has unclear requirements or you are working on a startup, you are unlikely to invest in microservices—it will be very expensive and require unnecessary time spent on preparation due to the need to implement DevOps practices. Conversely, by choosing a monolithic model, after you build a software development team and form the requirements for the project and its technical stack, they will be able to begin the development process immediately.

Development Simplicity 

For small projects and those that require moderate scaling, the development process in case of choosing a monolithic architecture will be simpler (in terms of the microservices vs monolithic architecture comparison) since it will not require the implementation of a peer-to-peer architecture, as well as the introduction of automated testing, debugging, and deployment tools.

Easier Debugging and Testing

Debugging and testing of small and midsize monolithic projects is easier than that of their microservice alternatives. The advantage of microservices is achieved only in the long term when the project has to be constantly updated and modernized. If this is not the case, you should look at the monolithic approach first.

Fast Deployment

The same in our microservices vs monolithic architecture comparison applies to deployment in the early stages of the life cycle of a software solution: if you don’t need to regularly enrich it with new features, deploying a monolithic architecture will be easier than in the case of microservices.

Low Cost in the Early Stages

Microservices are not about projects with strictly limited budgets. If you understand that every cent matters, it’s better to opt for a monolithic architecture (if your choice varies between monolithic architecture vs microservices), at least until you have the budget to implement such an approach.

Disadvantages of Monolithic Applications

Finally, let’s look at the disadvantages of monolithic architecture in terms of the microservices vs monolithic architecture comparison.

Hard Code Coupling

If you have a ready-made software solution that you decide to modernize through microservices, and your development team did not initially provide this option, code coupling can be challenging, to the point where your team will have to rewrite the entire code base from scratch. 

Slower Development Speed

Small monolithic architecture projects are developed faster compared to a microservice approach, which cannot be said about initially large-scale ones with rich functionality. In the second case, it will be easier for your team to initially turn to a microservice approach to simplify the implementation of individual services and be able to launch the entire project even while work on minor ones is not yet completed. 

Hard to Scale

Large-scale modernization of the application, which implies its regular enrichment with new functions, can be a tough nut to crack for a monolithic architecture. Moreover, in some cases, it’s completely impossible. That’s why, in the monolithic architecture vs microservices pair, it’s better to choose the second option.

Poor Reliability

If one of the functions of a monolithic application fails, this leads to the incapacity of the entire system. This can be unacceptable in some business areas and result in extremely costly downtime.

Performance Issues

The hierarchical structure of monolithic applications, after numerous updates and upgrades, can have serious performance problems while scaling through microservices horizontally expands the peer-to-peer dependency network between autonomous services, while maintaining the required performance level.

Differences Between Microservices and Monolithic Architecture

Now, let’s look at the difference between monolithic architecture and microservices from a software lifecycle perspective.

Development process

In the early stages of the project life cycle, it is always easier to start working on it by following a monolithic model—for this, your team will not need to prepare your IT infrastructure by complicating it with new DevOps tools. However, as your project becomes more complex, working on its updates will take more and more time and, at some point, may even require creating a new application from scratch.

Regarding microservices, then the initial meticulous planning will increase the efficiency of your team during further code maintenance while making changes in it and bug fixing as quickly as at the very beginning.

Debugging

Debugging a monolithic application allows specialists to use a single environment to identify incorrect system behavior, while debugging a microservices-based application may involve the need to coordinate testing procedures due to the fact that individual services may be developed by separate teams. 

Deployment

When comparing the initial monolithic architecture vs microservices deployment, monolithic deployment is faster because it occurs in a single environment. Individual microservices can be deployed by teams in environments for which they were specifically developed, which makes this process more complex and demanding from an administration point of view. Containerization can significantly optimize this task, but its benefits are achieved only if there is a regular need to deploy new project functions and services.

Updates

When there is a need for regular updates for an existing software solution, microservices allow teams to significantly gain time—both by reducing the scope of work associated with testing and from automated deployment. Conversely, the need to regularly update a monolithic application can become a real challenge even for experienced teams (because of the large number of dependencies and the total amount of code that will have to be rewritten), which at some point may become impossible to overcome.

Scaling

Finally, when comparing monolithic architecture vs microservices, we can say that the first one implies the combination of all functions in a single code base, which entails the need to make significant changes to the project with possible downtime in its operation. In the case of microservices, scaling is less resource-intensive due to the support of distributed systems, each of which can be updated as needed without affecting the others.

Monolithic vs Microservices: The Best Architecture Choice

Having assessed all the advantages and disadvantages of monolithic architecture vs microservices, we can conclude the following.

Microservices will be the best if:

• You create a complex system from scratch, and it implies constant scalability
• You are ready to introduce new, advanced tools for automated testing, deployment, and software development processes
• You need to implement a large number of technologies in your project
• You need a solution with increased fault tolerance

Monolithic Architecture are best if:

• Your application is not large enough to be split into microservices (with the right approach to coding, you can do this later)—in this case, the cost of each line of code will be unreasonably expensive
• The delay in transferring data from nanoseconds (which is achievable with monolithic architectures) to microseconds can be critical
• Your project’s code base is outdated, and before moving to microservices, you’ll need to undergo a major overhaul for the entire application, which can be too expensive and time-consuming

Final Thoughts

Summarizing the difference between monolithic architecture and microservices we highlighted above, we can say that, in our monolithic architecture vs microservices comparison, the latter is often the better choice since it’s one of the best solutions for solving problems of scalability of program code. However, following this architectural style just because it’s one of the most promising web development trends is not the best choice and can sometimes entail unnecessary costs and time. 

Therefore, if you want to get the optimal solution for your project, you will need to turn to a seasoned team with extensive experience working on software solutions of various sizes. In particular, you can contact us, and NIX will select the most effective way to implement your business idea. You can also get even more useful insights on how to build a web application here.