Microservices are a popular architectural approach to building modern software applications. Many organizations are interested in moving from a monolithic architecture to a microservices architecture in order to take advantage of the benefits that microservices offer. However, moving to a microservices architecture is not always straightforward, and there are some best practices to keep in mind when creating microservices from an existing monolith. In this article, we'll explore some of the key best practices to keep in mind when creating microservices from an existing monolith.

1. Start with a small set of services: It's important to start with a small set of services when creating microservices from an existing monolith. This allows you to test the architecture and make changes as needed before moving on to more complex services.

2. Identify bounded contexts: Bounded contexts are the areas of the application that have a clear and well-defined purpose. Identifying bounded contexts is important because it allows you to break the monolith into smaller, more manageable pieces.

3. Avoid shared databases: Shared databases can create tight coupling between services, which can make it difficult to change or replace individual services. Instead, each microservice should have its own database.

4. Use asynchronous communication: Asynchronous communication can help to reduce dependencies between services and make it easier to scale individual services.

5. Design for failure: Microservices are inherently more complex than monolithic applications, and failures can occur at any time. Designing for failure means that you should plan for failures and build systems that can recover quickly.

6. Monitor and test: Monitoring and testing are critical to the success of a microservices architecture. Each microservice should be thoroughly tested, and monitoring should be put in place to detect issues and performance problems.

7. Use API gateways: API gateways can help to simplify the management of microservices by providing a single entry point for all requests to the microservices architecture. They can also provide authentication and authorization, caching, and load balancing.

8. Use a service registry: A service registry is a directory of all the microservices in the architecture. It allows services to discover and communicate with each other without having to hardcode specific endpoints.

9. Embrace DevOps practices: DevOps practices such as continuous integration and continuous deployment can help to ensure that changes are deployed quickly and reliably. This is especially important in a microservices architecture, where many services may need to be updated or replaced on a regular basis.

In conclusion, creating microservices from an existing monolith can be a complex process, but by following best practices such as starting with a small set of services, identifying bounded contexts, avoiding shared databases, designing for failure, monitoring and testing, and embracing DevOps practices, you can successfully transition to a microservices architecture and take advantage of the benefits that microservices offer.