Microservice Interview Questions

Microservice Interview Questions

The inception of Microservices was initiated at a software architects workspace in Venice. The concept of Microservice Architecture or Microservices came into being in May 2011. Soon, the theory of Microservices was transmitted among the dominant companies and firms across the world. It aims to develop an extensive application in the shape of distinct components. The components or modules prefer to work individually but under the same business program. Due to its simple operation and flexible services, the demand for Microservices is increasing day by day. Microservices has already established its name in the market for its services related to enterprise solutions, and now, the organizations are demanding its services for producing cloud services.

In this article, we have presented some of the most common questions regarding Microservices that are asked in the interviews. If you’re keen to build your career in this field and desire to impress the interviewers, then these questions and answers might be helpful to you.

Microservices Interview Questions and Answers

Following is the set of top 20 questions with their most probable answers that are commonly asked in a Microservices interview.

1. What do you know about Microservices?

Ans: Microservices are an architectural-based model that is commonly used to create applications. It offers a quick, reliable service of delivering bulky and composite applications. Microservices are dispersed and lightly coupled; if you wish to make a slight change in one team, then it won’t disrupt the whole application.

Offering a variation of architectural styles, Microservices are also regarded as Microservices architecture. The applications that are built by a Microservice are a group of minor independent services that are developed and deployed for a commercial domain.

2. What are the key attributes of Microservices?

Ans: Here are the key attributes of Microservices:

  • Manifold Components that can be deployed individually
  • Services based on Commercial Competences
  • Management of Decentralized Data
  • Execution of DevOps
  • Infrastructure Computerization
  • Methodical Individuality
  • Concealed Constituent Intricacies to evade redundant microservices dependencies.

3. Name the main components of Microservices.

Ans: The main components of Microservices are:

  • Containers, Clustering, and Orchestration
  • Cloud Infrastructure
  • IaC (Infrastructure as Code Conception)
  • API Gateway
  • Enterprise Service Bus
  • Service Delivery

4. State the functioning postulates of a Microservice Architecture.

Ans: Microservices can be streamlined into various components that can individually implement a single task. Here are the functioning postulates of a Microservice Architecture.

  • The Microservice architecture can be split into several loosely coupled components where each of them will be deployed to perform a specific task.
  • It is circulated through clouds and data management centers.
  • The components used in this architecture are all independent and can be easily traded, updated, or removed without troubling the rest of the application.
  • The Microservice architecture says that an application can develop alongside its supplies.

5. Mention the advantages and disadvantages of Microservices.

Ans: The advantages of using Microservices are:

  • Due to its flexible nature, microservices can practice various technologies.
  • It features the fault isolation technicality that means whenever there will be a failure in a small process, it won’t break down the entire system.
  • It can develop and deploy multiple services at the same time.
  • Microservices reduce the time to deploy a service.
  • It allows autonomous deployment.
  • Provides security to every service.
  • It has a fast release cycle.

The disadvantages of using Microservices are:

  • Troubleshooting is a drawback of Microservices.
  • It sometimes becomes uncontrollable since it has a lesser amount of fault tolerance.
  • Microservices require more load balancing.
  • It fails to manage numerous services simultaneously.
  • Testing of services becomes complex across a distributed environment.

6. What are the tools that are used for Microservices?

Ans: Mostly, three tools are used for Microservices. They are:

  • Wiremock
  • Docker
  • Hystrix

7. What do you mean by Spring Cloud and Spring Boot?

Ans: Spring Cloud: Spring Cloud can be defined as a system that incorporates external systems. It is a momentary framework that is designed to make applications rapidly. Because of its connotation with a set of data processing units, Spring Cloud plays a substantial role in the architecture of Microservices.

Spring Boot: Spring Boot in Microservices is an open-ended framework that offers a platform for developers to build standalone spring applications. It helps the system to enhance its productivity, and it also reduces the time to develop and deploy.

8. What role does the Actuator play in Spring Boot?

Ans: An Actuator offers an opportunity to the RESTful web services to gain entry to the present state of an ongoing application. Besides this, a Spring Boot actuator also helps to monitor and handle the usages of an application without the need for the code or configuration setting of those applications.

9. Can the default properties of a Spring Boot project be overridden?

Ans: Yes, it is possible to override the default properties of a Spring Boot project by defining the properties in the application.properties file.

Example: In any application, you have to define a suffix and prefix for that application. Add the below-mentioned properties into the suffix and prefix section of the application.properties file.

For suffix – spring.mvc.view.suffix: .jsp

For prefix – spring.mvc.view.prefix: /WEB-INF/

10. State the problems that a Spring Cloud can handle.

Ans: A Spring Cloud can manage the below-mentioned problems:

  • Complex issues that are triggered by distributed systems
  • Issues related to the Service Discovery
  • Concerns about Load balancing
  • Redundancy disputes
  • Decreases issues related to the performance of the system

11. Differentiate between Microservices and Monolithic Architecture.

Ans: The differentiation between Microservices and Monolithic Architecture:

Microservices Monolithic Architecture
It requires less time to startup It requires more time to startup
Loosely coupled architecture Tightly coupled architecture
If you make a change in one model, it won’t affect the other models. Any changes in Monolithic Architecture will affect the whole system
Microservices primarily pay attention to products Monolithic Architecture pays attention to the entire project

12. What is Domain-Driven Design?

Ans: Domain-Driven Design is a design that follows the architectural style and is centered on the concepts and principles of Object-Oriented Analysis Design. The Domain-Driven Design involves components related to the software system to transform a complex system into an incessantly developing system. It has three principles:

  • Pay attention to the central domain and logic of the domain
  • Basing composite designs and strategies on a model of the domain
  • Join forces with the domain expertise to develop the application style and settle any issues related to the domain

13. What do you mean by OAuth?

Ans: OAuth (Open Authentication) is an open-standard authorization protocol or framework. It enables the user to gain entry to the client application via any third-party providers, including GitHub, Facebook, etc. It allows the user to share information and resources that are kept on one website to the other, without the need for a username and password. Access to the resources is also allowed by OAuth from the resource owner via the third-party providers.

14. What do you mean by Coupling and Cohesion?

Ans: Coupling is defined as a relationship between two modules, and it validates how much one module is dependent on another module. A coupling can be classified into three types: Highly Coupled, Loosely Coupled, and Uncoupled. Among them, Loose Coupled is the best type that can be accomplished over interfaces.

Cohesion, on the other hand, is a relationship between two or more elements within a single module. A module with high cohesiveness can execute a definite task with utmost efficacy without interconnecting with the other modules. The functional efficiency of a module increases if it has high cohesion.

15. Explain end-to-end testing of Microservices.

Ans: The end-to-end testing of Microservices is used to authenticate the progress of every process. It confirms whether every process is operating properly or not. It also validates that the entire system is functioning together as a unit and achieves all the client requirements.

16. What is Distributed Transaction?

Ans: A Distributed Transaction in Microservices is an event that distances compound databases over the network belt without disparaging the ACID properties. Let us assume that there is a transaction that has two services A and B. If both the services require writing to their databases and rollback if either of the two services fails, then we can say that this is a distributed transaction.

17. State the different approaches of Microservices Deployment.

Ans: The different approaches of a Microservice Deployment are:

Multiple Service Instance per Host: It is used to execute an instance of a single or a multiple service application either on a single physical/virtual host or on multiple physical/virtual hosts.

Service Instance per Host: This strategy is used by Microservice deployment to execute a service instance for each host.

Service Instance per Container: Microservices uses this strategy to execute a service instance for their corresponding container.

Serverless Deployment: It helps to bundle the service into a ZIP file and then transmits it to the Lambda function. The Lambda function is a service without any states that mechanically execute adequate microservices to maintain all the requests.

18. What do you mean by RESTful in Microservices?

Ans: RESTful or Representational State Transfer is a web service that is based on the architectural model that helps the system of a computer to impeccably communicate and link with other devices across the web. These web services are useful for comprehending and organizing a Microservice.

19. What is the utilization of containers in Microservices?

Ans: Containers are the simplest yet the most productive technique to cope up with Microservice-based applications. It aids as a software development program that helps the user with the development and deployment of an application individually. A container permits the user to compress their requirements within the image of a container. The best example of a container is Docker.

20. What is an API Gateway?

Ans: API Gateway is a management tool of Microservices that is used to meet the obligation of a single client application. It works as a backend resource that has only one entry point, and because of the single entry point, there are complications like observing, dependability, and resilience. NGINX and NGINX Plus are the two best API Gateways that are used for Microservices.


So these were some of the commonly asked interview questions on Microservices. If you appear for a Microservices interview, then go through the above-mentioned questions to get the best possible outcome. We have accumulated this information from multiple resources. However, one should not reflect this list as the decisive one. Also, try to consult more reference books and guides to get updated with the latest Microservices interview questions.

When you appear for the interview, be confident and don’t get panicked. Try to correctly answer the maximum number of questions. We wish you all the best for your Microservice Interview, and we hope that you get your dream job in this field.


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