Microservices vs. Monolith
Published: 2021-04-22 18:46:28

MONOLITHIC ARCHITECTURE

The monolithic architecture is considered to be a traditional way of building applications. A monolithic application is built as a single and indivisible unit. Usually, such a solution comprises a client-side interface, a server side-application, and a database. It is unified and all the functions are managed and served in one place. 
Normally, a monolithic applications have one large code base and lack modularity. If developers want to update or change something, they access the same code base. So, they make changes in the whole stack at once. 

STRENGTHS:
- Simplicity: Monolithic architectures are simple to build, test and deploy. These apps can scale horizontally, in one direction, by running several copies of the application behind a load balancer. 
- Cross-cutting concerns: With a single codebase, monolithic apps can easily handle cross-cutting concerns, such as logging, configuration management and performance monitoring. 
- Performance: Components in a monolith typically share memory which is faster than service-to-service communications using IPC or other mechanisms. 

WEAKNESSES:
- Reliability: An error in any of the modules in the application can bring the entire application down.
- Updates: Due to a single large codebase and tight coupling, the entire application would have to deploy for each update.
- Technology stack: A monolithic application must use the same technology stack throughout. Changes to the technology stack are expensive, both in terms of the time and cost involved. 

MICROSERVICES ARCHITECTURE

While a monolithic application is a single unified unit, a microservices architecture breaks it down into a collection of smaller independent units. These units carry out every application process as a separate service. So all services have their own logic and the database as well as perform the specific functions. 
Within a microservices architecture, the entire functionality is split up into independently deployable modules which communicate with each other through defined methods called APIs. Each service overs its own scope and can be updated, deployed, and scaled independently. 

STRENGTHS:
- Scalability: To scale a microservices-based application, you only need to scale certain components, which optimizes resource usage.
-Low coupling: Microservices components are loosely coupled so they are not interdependent and can be tested individually. It also makes the application more adaptable for changes over time. 

WEAKNESSES: 
- Team expertise: The benefits of microservices are moot without a prepared staff. You should assess the skills of you team members before moving forward with a microservices architecture. 
- Testing and monitoring: Once you break apps into components, you'll have more moving parts to track and eventually fix. Without the right testing and monitoring tools in place, things could quickly spin out of control. 

Sources: 
https://www.n-ix.com/microservices-vs-monolith-which-architecture-best-choice-your-business/#:~:text=While%20a%20monolithic%20application%20is,as%20perform%20the%20specific%20functions.
https://searchapparchitecture.techtarget.com/tip/Pros-and-cons-of-monolithic-vs-microservices-architecture

YouTube Video:  https://youtu.be/8awFYSOFUnY