Top 34 Microservices Interview Questions And Answers 2023

Microservices Questions

Q1.What Is Spring Boot?

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Spring boot is a major topic under the umbrella of microservices interview questions.

With the new functionalities that have been added, Spring keeps getting more complex. Whenever you are starting a new project, it is mandatory to add a new build path or Maven dependencies. In short, you will need to do everything from scratch. Spring Boot is the solution that will help you to avoid all the code configurations.

Q2.Define Domain Driven Design

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The main focus is on the core domain logic. Complex designs are detected based on the domain’s model. This involves regular collaboration with domain experts to resolve issues related to the domain and improve the model of the application. While answering this microservices interview question, you will also need to mention the core fundamentals of DDD.

Q3.How Does PACT Work?

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PACT is an open source tool. It helps in testing the interactions between consumers and service providers. However, it is not included in the contract, increasing the reliability of the application. The consumer service developer starts by writing a test which defines a mode of interaction with the service provider. The test includes the provider’s state, the request body, and the response that is expected. Based on this, PACT creates a stub against which the test is executed. The output is stored in a JSON file.

Q4.Why Do We Need Containers for Microservices?

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To manage a microservice-based application, containers are the easiest alternative. It helps the user to individually deploy and develop. You can also use Docker to encapsulate microservices in the image of a container. Without any additional dependencies or effort, microservices can use these elements.

Q5.What Are the Ways to Access RESTful Microservices?

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Another one of the frequently asked microservices interview questions is how to access RESTful microservices? You can do that via two methods:

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Using a REST template that is load balanced.

Using multiple microservices.

Q6.What Do You Mean by Bounded Context?

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A central pattern is usually seen in domain driven design. Bounded context is the main focus of the strategic design section of DDD. It is all about dealing with large teams and models. DDD works with large models by disintegrating them into multiple bounded contexts. While it does that, it also explains the relationship between them explicitly.

Q7.What Is a Client Certificate?

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This is a type of digital certificate usually used by client systems for making a request that is authenticated by a remote server. It plays an important role in authentication designs that are mutual and provides strong assurance of the identity of a requester. However, you should have a fully configured backend service for authenticating your client certificate.

Q8.Why Do People Hesitate to Use Microservices?

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I have seen many devs fumble over this question. After all, they’re getting asked this question when interviewing for a microservices architect role, so acknowledging its cons can be a little tricky. Here are some good answers:

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They require heavy investment – Microservices demand a great deal of collaboration. Since your teams are working independently, they should be able to synchronize well at all times.

They need heavy architecture set up – The system is distributed, the architecture is heavily involved.

They need excessive planning for handling operations overhead – You need to be ready for operations overhead if you are planning to use a microservices architecture.

They have autonomous staff selection – Skilled professionals are needed who can support microservices that are distributed heterogeneously.

Q9.What Do You Mean by End-To-End Testing of Microservices?

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End-to-end testing validates all the processes in the workflow to check if everything is working as expected. It also ensures that the system works in a unified manner, thereby satisfying the business requirement.

Q10.Role of Actuator in Spring Boot

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It is one of the most important features, which helps you to access the current state of an application that is running in a production environment. There are multiple metrics which can be used to check the current state. They also provide endpoints for RESTful web services which can be simply used to check the different metrics.

Microservices Interview Questions

Q1.How Do You Override a Spring Boot Project’s Default Properties?

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This can be done by specifying the properties in the application.properties file.

For example, in Spring MVC applications, you have to specify the suffix and prefix. This can be done by entering the properties mentioned below in the application.properties file.

Q2.What Is Semantic Monitoring?

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It combines monitoring of the entire application along with automated tests. The primary benefit of Semantic Monitoring is to find out the factors which are more profitable to your business.

Q3.How Can You Set Up Service Discovery?

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There are multiple ways to set up service discovery. I’ll choose the one that I think to be most efficient, Eureka by Netflix. It is a hassle free procedure that does not weigh much on the application. Plus, it supports numerous types of web applications.

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Eureka configuration involves two steps – client configuration and server configuration.

Client configuration can be done easily by using the property files. In the clas spath, Eureka searches for a eureka-client.properties file. It also searches for overrides caused by the environment in property files which are environment specific.

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For server configuration, you have to configure the client first. Once that is done, the server fires up a client which is used to find other servers. The Eureka server, by default, uses the Client configuration to find the peer server.

Q4.What Is Idempotence and How Is it Used?

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Idempotence refers to a scenario where you perform a task repetitively but the end result remains constant or similar.

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Idempotence is mostly used as a data source or a remote service in a way that when it receives more than one set of instructions, it processes only one set of instructions.

Q5.How Would You Perform Security Testing on Microservices?

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Before answering this microservices interview question, explain to the interviewer that microservices cannot be tested as a whole. You will need to test the pieces independently.

Q6.How to Configure Spring Boot Application Logging?

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Spring Boot comes with added support for Log4J2, Java Util Logging, and Logback. It is usually pre-configured as console output. They can be configured by only specifying logging.level in the application.properties file.

Q7.What Is Conway’s Law?

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Conway’s Law states, “organizations which design systems … are constrained to produce designs which are copies of the communication structures of these organizations.”

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The interviewer may ask a counter microservices interview question, like how is Conway’s Law related to microservices. Well, some loosely coupled APIs form the architecture of microservices. The structure is well suited to how a small team is implementing components which are autonomous. This architecture makes an organization much more flexible in restructuring its work process.

Q8.What Is OAuth?

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Open Authorization Protocol, otherwise known as OAuth, helps to access client applications using third-party protocols like Facebook, GitHub, etc., via HTTP. You can also share resources between different sites without the requirement of credentials.

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OAuth allows the account information of the end user to be used by a third-party like Facebook while keeping it secure (without using or exposing the user’s password). It acts more like an intermediary on the user’s behalf while providing a token to the server for accessing the required information.

Q9.Explain the term ‘Continuous Monitoring.’

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Continuous monitoring is a method which is used for searching compliance and risk issues associated with a company’s operational and financial environment. It contains human, processes, and working systems which support efficient and actual operations.

Q10.How independent micro-services communicate with each other?

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It depends upon your project needs. However, in most cases, developers use HTTP/REST with JSON or Binary protocol. However, they can use any communication protocol.

Microservices Questions And Answers

Q1.What is the use of Docker?

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Docker offers a container environment which can be used to host any application. This software application and the dependencies that support it which are tightly-packaged together.

Q2.What are Reactive Extensions in Microservices?

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Reactive Extensions is also called Rx. It is a design pattern which allows collecting results by calling multiple services and then compile a combined response. Rx is a popular tool in distributed systems which works exactly opposite to legacy flows.

Q3.What is the meaning of Semantic monitoring in Microservices architecture?

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Semantic monitoring combines automated tests with monitoring of the application. It allows you to find out reasons why your business is not getting more profits.

Q4.Explain the use of PACT in Microservices architecture?

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It is an open source tool which allows testing interactions between service providers and consumers. However, it is separated from the contract made. This increases the reliability of the Microservices applications.

Q5.What is the meaning of OAuth?

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OAuth means open authorization protocol. This protocol allows you to access the client applications on HTTP for third-party providers GitHub, Facebook, etc. It helps you to share resources stored on one site with another site without the need for their credentials.

Q6.What is End to End Microservices Testing?

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End-to-end testing validates every process in the workflow is functioning correctly. It also ensures that the system works together as a whole and satisfies all requirements.

Q7.What is a CDC?

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CDC is Consumer-Driven Contract. It is a pattern for developing Microservices so that external systems can use them.

Q8.In which cases microservice architecture best suited?

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Microservice architecture is best suited for desktop, web, mobile devices, Smart TVs, Wearable, etc.

Q9.Tell me the name of some famous companies which are using Microservice architecture

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Most large-scale websites like Twitter, Netflix, Amazon, have advanced from a monolithic architecture to a microservices architecture.

Conclusion:

So these are some of the most popular microservices interview questions that you need to be aware of. Practice these questions and prepare a good answer for these questions as these might be asked in the interview. Overall, these won’t be the only question that would be asked but you can certainly help yourself out with these questions. Thank you for staying and we hope that you liked our article and found everything you hoped.