Every tech company nowadays thinks twice about the architecture of their server-side apps. so in this article, we will chat about the trends in architecture and how to choose the optimal solution for your application.

Monolith :

A monolith server-side app is an application delivered by single deployment, with all the business logic in one place, Users interact with the application through a singular API.

- Pros :

• Simple architecture.
• Easy to run, test/debug and maintain.
• The fastest way to build and deploy.
• Low response time

- Cons :

• Risk of a single point of failure
• Limited scalability (can scale vertically (add memory, CPU) but not horizontally).
• Difficult to adopt new technologies independently (it's difficult to have different techs in one monolith

The monolith architecture is popular due to its simplicity making it well-suited for smaller/medium applications or projects.

Micro-Services :

A microservice server-side app or microservices, is an application constructed with a collection of independent services, each service has its unique responsibility.

- Pros :

• Scalability ( you can scale vertically/ horizontally).
• You can optimize and scale a specific service.
• Resilience to failures in one service doesn’t affect the entire system.
• Independent service updates.
• You can mix technologies (each service can be developed with the optimal tech)

- Cons :

• Complex to design, develop, test, and manage.
• Implementing robust inter-service communication mechanisms can be complex.
• Managing a larger number of services introduces operational overhead, including monitoring, logging, and deployment coordination.

Microservices architecture has gained popularity due to its scalability and flexibility(each service can be developed with the optimal tech), making it well-suited for larger and more complex applications.

This strategy includes breaking down complex systems into independent services each developed with the optimal technology. However, this flexibility requires a skilled team knowledgeable in various technologies, adding complexity to configuration and ensuring seamless interactions between these services.

Serverless :

Serverless, or Function as a Service (FaaS) is a cloud computing model that enables developers to run individual functions in response to events without the need to manage servers.

In a serverless architecture, developers focus on writing code for individual functions, and the cloud provider takes care of the infrastructure, handling events, and automatically scaling resources as needed.

- Pros :

• Automatic Scaling.
• Simplified Deployment: Developers focus only on writing and deploying the functions.
• Resilience to failures in one service doesn’t affect the entire system.
• Easy maintenance (No infrastructure or OS to maintain).

- Cons :

• Bad response time (cold starts).
• Limited control.
• Dependency on Third-Party Services.
• Limited Execution Time (Serverless platforms often impose constraints on the maximum execution time for functions).

Serverless architecture frees developers from managing server infrastructure. It’s an ideal choice when rapid scalability and cost efficiency are required (you pay only for the actual computing resources used during execution). However, it’s important to note that cost efficiency can only be achieved if the architecture is handled properly. Otherwise, you may end up paying more than expected due to the cost of individual services in the cloud.

Results (in my opinion) :

Practical approach :

In the real world, the popular approach is progressively creating an architecture that is a mix of the three.

For example for the beginning of the project to quickly build to prototype we start with what we call modular monolith it’s better than monolith because it is cleaner (better dev experience) :

Then we can optimize the architecture a bit by moving the auth module to its independent service :

So you can be creative with mixing to create an optimal solution for your project.

Conclusion :

In the wild world of server-side setups, the decision between Monolith, Microservices, and Serverless profoundly impacts an application’s performance and scalability. Crafting a high-performing app involves not blindly following trends but strategically selecting or blending these architectural paradigms to align with your business criteria and budget constraints.

It’s not just about writing code, it’s about being the engineer who picks the perfect plan for success.