Increased complexity

Nothing is free in this world. Implementing microservices requires a lot of additional infrastructure, such as service discovery, load balancing, and inter-service communication. This can increase the complexity of your system and make it harder to maintain.

2. More difficult testing

With Microservices, Testing becomes more complex as each service must be tested individually, as well as in conjunction with other services that it depends on.

3. Higher deployment costs:

Because microservices involve multiple services running independently, deploying and maintaining them can be more expensive than deploying and maintaining a monolithic application.

4. Increased operational overhead

If you ask me, managing and supporting one service is always easier then managing 100s of them even if they are smaller. With Microservices, you have to manage and monitor multiple services, which can add to your operational overhead.

5. Distributed systems are harder to debug

This is probably the most important reason for me to avoid Microservices for everything I build. When something goes wrong in a distributed system, it can be difficult to identify the root cause of the problem.

6. Higher latency

Microservices communicate with each other over the network, which can introduce additional latency into your system. This one is also a popular Microservice question where interviewer commonly ask on which scenario using Microservices is not desirable? while there are many but latency sensitive applications should be built on Microservice architecture.

7. Difficult to reason about

With multiple services running independently, it can be harder to understand how they all fit together and how data flows through the system.

Difference between Microservices and Monolithic Architecture for Java Interviews

What are differences between Monolith and Microservices architecture? Pros and cons, and when to use each of them

medium.com

8. Requires a team with specialized skills

Microservices require a team with specialized skills in areas such as distributed systems, networking, and DevOps.

10 Things to Keep in Mind while Designing and Developing Microservices

Best practices and considerations for building effective microservices architecture

medium.com

9. Security concerns

Securing a microservices architecture can be more challenging than securing a monolithic application. Though, you can use framework and libraries like Spring Security, JWT and OAuth 2.0 its still challenging to secure Microservices. If you want to learn more, see my earlier article about securing microservices:

10. Not always necessary

For smaller applications, a monolithic architecture might be perfectly suitable and implementing microservices might be overkill. So stick to what suits best for your requirement.