Choosing the best software architecture style for your app is not a trivial decision. It can affect the quality, performance, scalability, maintainability, and security of your app. But how do you know which style suits your app's needs and goals? In this article, we will explore some of the most common and popular software architecture styles and their benefits and drawbacks.
A monolithic architecture is a style where the app is built as a single unit, with all components tightly coupled and running in the same process. This style is simple to develop, test, and deploy, as there are no dependencies or communication issues between components. However, as the app grows in size and complexity, it can become difficult to scale, modify, or maintain. Additionally, it can introduce performance bottlenecks if a failure in one component affects the whole app. Moreover, this architecture can limit the choice of technologies since all components must use the same language and framework.
I can expand on few more drawbacks for monolithic applications: a. A small code change in application requires rebuilding and re-deployment of the entire monolithic application. b. One cannot scale individual components. Scaling has to happen for the entire application even if only one component needs scaling, resulting in wastage of compute resources (CPU, RAM). c. If there is one error/exception in one module, then it affects the entire application. It works as all or nothing. d. Maintainability is a nightmare, as we need to do thorough impact analysis of the dependent components before making any code changes to a component. The enhancements or defect fixes requires complete knowledge of the monolithic application.
A microservices architecture is a style of app development where multiple independent and loosely coupled services, each with its own responsibility and domain, are composed together. This style is flexible, scalable, and resilient, as each service can be developed, tested, deployed, and updated independently and in parallel. However, this architecture has some challenges that need to be taken into consideration. For instance, it can increase the complexity and cost of development, testing, and deployment due to the increased number of services that need to be managed and coordinated. It can also introduce network latency, security risks, and data consistency issues due to the communication and synchronization between services over the network. Additionally, it can require more skills and tools from developers as they have to work with different technologies, protocols, and patterns.
I would like to add few missed drawbacks of microservices. a. As we write each microservices in a different language, we will end up with proliferation of languages, logging standards and monitoring tools. This results in high maintenance costs and lack of standardization. b. Each microservice can have different set of logs making the debugging difficult. Debugging is further complicated when a business process spans multiple machines having different microservices running in it as part of the business process.
A serverless architecture is a style of app development that utilizes cloud-based services to provide the functionality and resources on demand, without requiring the developers to manage or provision servers. This is an efficient, scalable, and cost-effective approach, as the app only pays for the resources it consumes and can handle variable workloads. However, it can also reduce control and visibility over the app's performance, reliability, and security as developers depend on the cloud provider's services and policies. Furthermore, it can create vendor lock-in, as the app becomes dependent on the cloud provider's specific features and interfaces. Additionally, it may increase the cold start time due to waiting for the cloud services to initialize and respond.
One of the most common serverless architecture pattern is FaaS (Function as a Service). Using this architecture, we can invoke the FaaS functions based on specific events. This architecture in my opinion is suited only for very specific use cases that too in cloud-based solutions. It is not applicable in on-premises solutions.
An event-driven architecture is a style where the app is based on the production and consumption of events, messages that represent changes in the state or behavior of the app. This style is reactive, responsive, and scalable, able to adapt to changes and demands in real time and distribute the workload among different components. However, it also has some drawbacks such as creating a complex and unpredictable flow of events, introducing data loss, duplication, or inconsistency, and requiring more monitoring and debugging tools. It's important to remember that there isn't one-size-fits-all solution for choosing the best software architecture style for your app. You need to consider your app's requirements, constraints, and trade-offs while evaluating the pros and cons of each style. Ultimately, you must find the balance between simplicity and complexity, flexibility and consistency, efficiency and reliability that works best for your app.
I completely agree that there isn't one-size-fits-all solution for choosing the best software architecture style for your app.