Interview questions for Mule soft developer

1. What is MuleSoft?

MuleSoft is an integration platform for connecting enterprise and SaaS applications in the cloud and on-premise.

2. List types of variables in MuleSoft?

Types of variables in MuleSoft are:
• Flow Variable: It is used to either set or removes variables tied to a particular message in the current flow.
• Record Variable: It is used for batch processing flows.
• Session Variable: This variable is used to either set or remove variables tied to a particular message for the complete lifecycle.

3. What is ESB?

ESB stands for Enterprise Storage bus. It’s software architecture for middleware and it provides fundamental services for more complex architectures. This is the common Mulesoft Interview Questions which is frequently asked in an interview.
Example: In ESB incorporates with the features required to implement an SOA(service-oriented architecture ).

4. What is the MuleSoft Anypoint platform and where it will be used?

MuleSoft Anypoint Platform of integration products is designed to tie both software as a service (SaaS) and on-premises software.

5. What are the various types of messages in MuleSoft?

Various types of messages in MuleSoft are: 1) echo and log message, 2) bridge message, and 3) build message.

6. What are the key differences between Mule 3 & Mule 4? What are the interfaces developed by you? Explain the flow

Explain the interfaces (how mule is involved in the integration & transformation) and APIs flow of your project. Also, explain the various connectors you have used for the implementation.

7. Which version of Mule you have used?

Based on your experience you can tell either Mule 3.9 or Mule 4.

8. What are the frontend & backend applications?

Explain the frontend application which sends the payload to Mule and the backend application to which the payload is sent.

9. What is fan-in?

Fan-in helps in taking a decision to continue flow execution. It be used in combination with fan out.

10. How will we identify ESB is needed in a project?

Implementation of ESB is not suitable for all the projects. We should analyze is really ESB is required here or not. You need to analyze by taking below points into consideration:
• In the project, require 3 or more applications and services to be integrated and there must be a need to communicate between the applications.
• If there is plain of interacting with more applications and Services in the future then we can go with Mule ESB because it is highly scalable.
• We need to keep cost also in mind before going to ESB implementation
Let us move to the next Mulesoft Interview Questions

11. Explain the difference between Callout and Service Invoke?

Callout: We can call the service using callout or with service invoke. Use the Callout if we need to mediate a message (without calling an intermediate service) and then call a service provider.
• The Callout provides the simplest model for this configuration.
Service Invoke: You need to interact with multiple services, and produce an output that combines service responses. The Service Invoke primitive does not switch from request flow to response flow.
• Use the Service invoke if we need to call an intermediate service.
Example: We can use an intermediate service to adjust a message or to validate a message externally. The mediation flow contains Service Invoke mediation primitive, and a Callout node that is connected to the service provider there will be no intermediate service

12. What is a fan-out?

Fan out is primitive that can be used to input messages through the output terminal once or more than one time. It can also be used as a combination of both fan-out and fan-in.

13. Mention the features of Mule ESB?

The features of Mule ESB are:
• Offer SLA (Service Level Agreement) monitoring and API management facility.
• It has easy to use and drag and drop graphical design.
• Mule ESB provides high scalability.
• It enables developers to deploy in one click cloud or on-premise deployments.

14. Mention the basic principles of ESB Integration?

The basic principles of ESB integration are:
• Transportation: It negotiates between different formats like JDBC, HTTP, JMS, etc.
• Transformation: It deals with the transportation of data between data formats needed by the ESP connector.
• Non-functional consistency: It is the way of how monitoring and security policies are applied and should be consistent.
• Mediation: It involves offering different interfaces to:
1. Enables different channels to the same component implementation.
2. Support various service versions for backward compatibility.

15. What is the definition of Web Services?

Web service is a function or program in any language that can be accessed over HTTP. Message format can be XML or JSON or any other program as long as the other programs can understand and communicate. Any web service has a server-client relationship. Web services can be synchronous or asynchronous. Any web service can have multiple clients.

16. Difference between URI & query parameters?

URI parameter is basically used to identify a specific resource or resources whereas a query parameter is used to sort/filter those resources

17. How to fetch URI & query parameters in Mule 4?

Attributes in Mule 4 replace inbound properties

18. What is the difference between ESB and JMS?

ESB provides the middleware and interfaces that allow businesses to connect their applications without writing code.
• JMS provides the messaging capability and facilitates communication between the modules/applications.