Why did you leave the monolith, what were the bottlenecks and response time issues?

The main reasons for leaving a monolith are related to scalability limitations and support complexity. In a monolith, all components are tightly coupled, leading to the following bottlenecks:

• Response time: When load increases, the entire monolith is scaled, which is inefficient and costly.
• Dependencies: Changing one part can affect others, increasing the risk of errors and testing time.
• Deployment: Updating requires restarting the entire application, reducing availability.

For example, if a payment processing module in a monolith is heavily loaded, it is impossible to scale only it — the entire service must be scaled, which is inefficient. This leads to response delays and reduced performance.

Transitioning to microservices allowed isolating bottlenecks into separate services, scaling them independently, and speeding up response times by optimizing specific components.