Microservices vs Monolith: which architecture is the best choice?

When you are planning to launch a startup or your existing software grows, which development path should you choose? Is it worth switching from monolith to microservices or continuing the “already formed” approach? What use cases should you depend on when making the ultimate choice? Answers to all these crucial questions we will clear up in our article.


  1. Understanding monolithic and microservices architectures
  2. Pros and cons of a monolith
  3. Benefits and challenges of microservices
  4. Microservices vs Monolith: Business use cases of two systems
  5. FreySoft case – WorldRemit
  6. What to choose for your project – monolithic or microservices approach?

Understanding monolithic and microservices architectures

Microservices and monolithic systems are types of IT solution architecture.

Monolithic architecture

Monolith is a type of software architecture where all functionality is in a single codebase and deployed as one unit. In case any code updates are required, they cannot be hosted separately. The developer must use the same codebase, make the necessary changes, and then redeploy the updated code.

Example of monolithic architecture:

Let’s imagine a classic e-commerce store. Standard modules are UI, business logic and data layer. Possible ways of interacting with the service are REST API and web interface. In a monolith, all of these elements will be managed within the same module.

Microservices architecture

Microservices is a type of software architecture where the focus is on creating of self-contained components that make up an application. Unlike monolith, which is built as a unit, the microservices system is made up of multiple independent components that are connected through APIs. It allows separate teams to work and coordinate different services, mostly on their own. 

Example of microservices architecture: 

Let’s again take an e-commerce store as an example. As before, we have UI, business logic, and data layer. However, all the above have their own service and their database. They are loosely coupled and can interoperate with different protocols across their boundaries.

It is widely spread using microservices system among global companies. To illustrate, the monolithic apps of Amazon and Netflix have grown into larger microservices infrastructures. As a result, they scaled, improved the performance and attracted larger audiences. 

However, that doesn’t mean that microservices are the best-suited trend for all projects and that monolith is a yesterday’s day solution. To understand what approach and when to apply, let’s take a more precise look at the advantages and disadvantages of each of the systems.

insights about microservices
Image source: pexels

Pros and cons of a monolith


The major distinct advantages of the monolith are:

  1. Fast and easy in deployment.

    Due to the simplicity of architecture, the development process is easy-to-start.

  2. Fewer security concerns.

    There is much greater security communication in one unified team than in the case with distributed teams.

  3. A single codebase.

    With a single codebase, it is easy to track bugs and conduct end-to-end testing.

  4. High performance

    Since the system is only loaded with one process,  the monolith generally has high throughput performance.

  5. Low cost.

    On contrary to microservices, monolith needs less cost spending. However, if scaling is necessary, you’ll need to contribute more money.


Meanwhile, the monolith approach faces the next key challenges:

  1. Technical debt.

    Within time, changes in demand and staff turnover, the software’s technical debt will gradually build up and accumulate. Consequently, the system design or used code would be difficult to change since other modules in the software may use it in unexpected ways.

  2. Vulnerable system.

    The application is relatively fragile and vulnerable to bugs since they often affect the entire system, not just the part of it.

  3. Limited scalability options.

    Monolithic applications can only be extended as a whole and cannot scale with the characteristics of the business modules.

  4. Complicated in integration with other systems.

    Adding third-party components to a single codebase requires complex connections to different tiers of the monolithic application.

  5. Obstacles to improving technology.

    Monolithic applications often use a single technology platform. Each team member must use the same development language and architecture. If you want to use a new technology or framework, you cannot do it in the application part. You have to rewrite the entire software.

The benefits and challenges of microservices 


Deployment. Due to short-in-time and flexible development and testing cycles, new versions of the services are fast-to-deploy. It provides flexibility in using security configurations, replication, persistence, and monitoring.

Scalability. Each microservice can independently be scaled, not influencing other components. To increase system performance, you only need to extend the services that requires it. 

Reliability. When a defect happens, it only affects that very microservice and its consumers. On the contrary, in a monolithic model, failure of service can lead to the destruction of the entire monolith.

Technological diversity. With microservices, it is easy to mix programming languages, development environments, and storage technologies.

Autonomy. The engineering and QA teams can independently use various technologies, frameworks, and templates to modify and redeploy each microservice. 

Data management. Each microservice contains its own volume of data that is available to other microservices only through the corresponding interface (decentralized data management). 

To finalize, we can assume the next points:

  • It is easier to change one microservice and immediately implement it than to change the entire monolith and restart the entire infrastructure.
  • On the contrary to monolith, microservices do not depend on any platform, making it easier to implement new technologies.
  • For new engineering teams or one developer, it is more effective and easier to get into work with microservices system. They do not need to study the entire architecture and can work only on their part.


The complexity of the initial design and infrastructure creation. Distributed systems are more difficult to design because you need to provide the independence of one microservice from failure in another component.

Organizational changes. Each team must cover the entire lifecycle of a microservice to be completely independent. From design and concept, technical solutions and implementation to ongoing operations and monitoring. This requires organizational changes, such as transferring authority from managers to teams. For this reason, culture DevOps is highly desirable for microservices’ projects.

High requirements for operation and maintenance. More services mean more investment in operations and maintenance. In a monolithic architecture, only one application needs to guarantee to work well; while in microservices, it is necessary to ensure that a number of services work efficiently.

Microservices vs Monolith: Business use cases of two systems

Using a monolithic architecture is an excellent choice in the next situations:


When you are launching a startup, your team is small, and you do not need to implement a complex architecture, then it makes sense to turn to a monolithic architecture. It can meet the needs of your business, and if necessary, you can change the architecture when you have the resources it requires.


A monolith is good-in-use for developing an MVP, since you complete the proof of concept with less complexity and in the quicklime way.

Single-page applications

If your application is simple and does not contain a lot of business logic, therefore, does not require modularity and scalability, then a monolithic architecture is for you.

On the contrary, microservices architecture is better for:

Complex large-scale projects

Microservices provide an efficient development approach that enables you to develop one application with multiple stand-alone teams; use different stacks for the necessary tasks for a single product; and implement decentralized data management, if required by the business.

A key tenet of this approach is that services can be deployed independently. So, when you make changes, you only need to test and deploy the very microservice. If you get tangled up in it, you will not bring down the entire system.

Multiple teams

In case new developers are required, it would be easy and fast-in-time to understand how a particular microservice works – he or very new teams just need to spend half a day reviewing all the necessary documentation surrounding it.

Your monolith software grows 

Making changes and then debugging monolithic software is a tedious task. Moving from a monolithic architecture to microservices makes the business more mobile and flexible. To illustrate the example of transferring from monolith to microservices, we will take the FreySoft case with our client WorldRemit.

FreySoft Case – WorldRemit

WorldRemit, a large-scale FinTech company, was in the process of rebuilding a monolithic project into microservices and introducing new payment methods. Over the years, the company has experienced rapid growth, which has resulted in:

  • limitations of the existing architecture,
  • limited operating resources to support new integrations.


WorldRemit was looking for the engineering resources to rapidly replace existing payment methods to equivalent Optile-related ones; to introduce new payment methods as well to increase its expansion over the world. Extending quickly with skilled teams from the FreySoft company has been an effective strategy to independently implement (including development, testing, support, customization, etc.) new methods. 

Implementation of service integration includes:

  • Get all necessary information documentation
  • Clear all technical gaps for integration (TLS/MTLS connection, authentication, mandatory fields, etc.)
  • Service implementation
  • Testing service in the test environment
  • Setup and configure service in the microservice architecture
  • Support ‘go-live’ step

QA team has completed several steps to archive WorldRemit’s goals:

  • implemented high-load and scalable services (over five different ones)
  • used flexible code structure to simplify maintenance
  • implemented several levels of manual and automated tests, which allowed FreySoft to have great test coverage (>85%) and avoid major and critical bugs in the production
  • implemented two levels of monitoring that allowed QA experts to quickly react to any issue in any environment
  • provided responsive support for business during the expansion of its new markets.


As a result, the product features high performance, reliability, and stability for customers all over the world. The project has actually helped to address the architectural tech debt. Without addressing this tech debt, it would be barely possible to further onboard new payment methods and providers.

The FreySoft DevOps team has improved cybersecurity, canceled several services in Azure, and updated automation. We have reached new standards and ways of developing the functions required by the client. Further adoption of new payment methods and providers has become much easier and less error-prone.

From a business perspective, it also allows the client to expand to new markets and decreases costs. Today, the platform is trusted by thousands of users and greatly improves customer satisfaction.

What to choose for your project – monolithic or microservices approach?

There is no one-size-fits-all answer on whether monolith or microservices is better. The choice must be made up to your specific project and business needs. However, we already can conclude: if your project does not plan high loads and the constant addition of interaction with external services (payment systems, banks, external storage, etc.), it is better to choose a monolith. And vice versa: if the system must operate under any load and with numerous services, then a microservice architecture is required.

Speaking about switching from monolith to microservices, we’ve noted a couple of scenarios in which you should consider this step:

  • when  the cost of new functionality in a monolithic project does not cover the expected benefit;
  • when the project tends to scale its boundaries. In microservices, you can take a separate component, determine what is happening in it, and work only with it. 
  • when the different teams are required within the software development and maintenance. In large projects, the separation of teams’ duties will sooner or later lead to architectural delimitations. Microservices make it easier to relive this moment.

Most importantly, let’s not forget about other issues that determine the success or failure of software development projects. Factors such as the quality of the people on the team, how well they interact with each other, how much they communicate with subject-matter experts will have a greater impact on the project.

FreySoft team has wide experience in the subject area, attentively pays attention to developers’ qualifications, release dates, project load, the number of external systems with which the project must exist. We take the best approach – we adapt to the features of your specific project and business tasks and based on it, choose the solution. Contact us and find out how we can help your business!

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