Monolithic vs Microservices: Services, where to use what ?

Introduction

The choice between a software application's monolithic or microservices design is based on a number of variables, such as the project's complexity, the team's level of experience, the business's unique demands, and the necessity for scalability. This is a quick rundown of each architecture and the situations in which one could be better than the other.

Monolithic Architecture

The Conventional Model: Consider a monolithic application as a sizable, integrated unit. Its user interface, business logic, and database access are all closely integrated into a single codebase and are deployed as a single unit.

• Pros:Simpler Development: Easier to develop and test initially, especially for small-scale projects.Straightforward Deployment: You have a single unit to deploy.
• Cons:Tight Coupling: Changes in one part can ripple and cause problems in other areas.Scaling Challenges: Scaling the entire application is necessary, even if you just need to enhance a specific area.Technology Lock-in: It's difficult to introduce newer technologies without major rewrites.
• Where to use:

• Small Teams or Projects: Monolithic applications can be easier to develop and deploy with smaller teams because they involve a single codebase and straightforward deployment processes.
• Simpler Applications: For applications with a limited scope or less complexity, monolithic architectures can be more efficient and easier to manage.
• Rapid Prototyping: When speed is of the essence, and you need to develop a prototype quickly, a monolithic approach allows for faster development cycles since there's no need to deal with the complexities of distributed systems.

Microservices Architecture

Focused Services: A microservices architecture resembles an assemblage of more compact, stand-alone services. Each service has its own:

1. Clearly defined business function
2. Codebase
3. Potentially its own database

• ProsAgility: Teams can work, develop, and deploy individual services without disrupting the entire application.Scalability: Scale specific services as needed, not the whole monolith.Technological Freedom: Choose the best tech stack for each service.
• Cons:Complexity: Designing, building, and managing distributed systems is more complex.Operational Overhead: You need sophisticated monitoring and coordination among services.Network Reliance: Services rely heavily on inter-service communication over the network.
• Where to Use:Large, Complex Applications: For applications that are expected to grow in complexity, adopting microservices can make the system more manageable and allow different teams to work on different services simultaneously.Scalability Requirements: If different components of your application have varying scalability needs, microservices allow you to scale these components independently, making the application more resource-efficient.Diverse Technology Stacks: Microservices support the use of different technology stacks across different services, enabling the use of the best tool for each specific task or service.DevOps and Continuous Deployment: Organizations with a strong focus on DevOps practices may find microservices beneficial, as they allow for continuous deployment and integration practices without impacting the entire application.

When to Choose Which

Here's a quick decision guide:

Lean Towards Monolithic If:

• You have a small, well-defined project.
• Your team is smaller and prefers a simpler architecture.
• Speed to initial release is a top priority.

Consider microservices if:

• Your application is large and has complex domains.
• You want flexibility to scale certain components independently.
• Embracing diverse technologies is crucial.
• Your team is comfortable with the added complexity.