Microservices Interview Questions (With Sample Answers)

By Indeed Editorial Team

Updated 16 October 2022

Published 6 June 2021

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

The microservices architecture enables you to develop web applications by combining several small independent modules instead of structuring the entire application as one single unit. With the increasing popularity of microservices, the demand for microservices developers may also increase in the future. Understanding common microservices interview questions can help you prepare well for your interview. In this article, we list some of the popular interview questions for microservices, along with tips on answering them.

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Beginner-Level Microservices Interview Questions

Here are some of the basic microservices interview questions for beginners:

  • How does microservices architecture differ from monolithic architecture?

  • What are the major characteristics of microservices architecture?

  • Name some of the commonly used tools in microservices.

  • What are the difficulties involved in using microservices architecture?

  • Describe some scenarios in which microservices architecture can be a good choice.

  • Can you name a few companies that use microservices?

  • What is a consumer-driven contract (CDC)?

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Advanced-Level Microservices Interview Questions

Following are some of the advanced-level microservices interview questions for experienced professionals:

  • How does Spring Boot help in microservices?

  • What does an actuator do in Spring Boot?

  • How do you implement Spring Security in a Spring Boot application?

  • Which embedded containers does Spring Boot support?

  • What is RESTful?

  • What is the use of PACT in microservices?

  • What is a client certificate?

  • What is OAuth?

  • Why do we use containers in microservices?

  • Explain the use of ReactiveX in microservices.

  • How do the independent components communicate with each other?

  • What do you know about coupling and cohesion?

  • What is bounded context?

  • What is Conway's law?

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Common Microservices Interview Questions And Answers

Here are some popular microservices interview questions, along with sample answers:

1. What is microservices architecture?

This is a basic question the interviewers ask to gauge your level of understanding of microservices architecture. Briefly explain the concept of microservices in simple and clear language. Frame your response in a way to convince the interviewer that you understand the concept and have not just memorised the definition.

Example: "The microservices architecture is a software development style in which we structure an application as an integrated unit of several small, independent modules. Each module is capable of independent functioning and deployment and is usually owned by a small team. The modules are loosely coupled and organised around a business domain. Since you need not develop the entire structure from scratch, the microservices architecture enables the rapid development of complex applications. It also facilitates easy updating, testing and maintenance."

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2. What are the major advantages of microservices architecture?

Microservices architecture offers some distinct advantages over traditional, monolithic architecture. You can include benefits like decentralised governance, technology diversity, agile development and ease of deployment in your answer.

Example: "Microservices architecture offers several advantages like technology diversity, automated development, independent deployment, fault isolation and easy up-gradation. Since microservices architecture has several independently functioning small modules, we can use a number of different technologies for a single application. We can automate product development because we just require to assemble the modules. Each module is capable of independent deployment, which saves us a lot of time and complications if we were to deploy the entire system at once.
In the case of a system failure, we can track down the defect to a specific module and rectify or replace it. Similarly, we can also upgrade technology at the modular level.”

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3. What is end-to-end testing in microservices?

The end-to-end testing holds a special significance in microservices because all the components require to work in harmony towards the application's common end. You just require to explain what end-to-end testing means without going into procedural details.

Example: "End-to-end testing is used to validate the functionality of each of the independent components. It also validates that all the components are working together efficiently as a system through a central hub. Each component is required to support the functionality of the application."

4. What is canary deployment in microservices?

Canary deployment refers to the release of a candidate version (deployment for testing purposes) to try out new features of a software product. Focus your answer on how canary deployment works in microservices.

Example: "Canary deployment is the process of testing a new version of the software by releasing it to a small group of users. Unlike in monolithic architecture, where we are required to test the entire application, microservices enable us to test a single feature of the application. We can also test multiple versions of the software simultaneously. If the monitoring team finds that the software is working as expected, they can make a full-fledged release to all users.
Sometimes, we can also make canary deployments in actual production, usually when we require to test some new features of a module or two. The impact on production due to such deployment is minimal due to the modular nature of the microservices architecture.”

5. Describe Spring Cloud in relation to microservices.

Given the distributed nature of microservices, Spring Cloud is essential for proper monitoring and administration of the system. Include some of the features of Spring Cloud in your response.

Example: “Spring Cloud has special relevance in microservices since it enables easy integration of the components with the system. Building a microservices system using Spring Cloud mitigates several challenges of a distributed architecture. Some of the notable features of Spring Cloud include service discovery, service-to-service calls, distributed tracing, routing, load balancing, cluster election and circuit breaking. It can also act as an API gateway.”

6. What is semantic monitoring?

Briefly explain the process of semantic monitoring. Be sure to include how it can help increase profitability for a business.

Example: “Semantic monitoring or synthetic monitoring combines the entire application monitoring with automated tests. It helps us identify the factors that are more profitable for the business. The process involves regularly running a set of automated tests for an application against the actual production system. We then require to feed the results into the monitoring service, which detects and alerts for failures in the production. Once we identify an issue, we can isolate and debug it.”

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7. Explain the uses of reports and dashboards in microservices.

Various tools allow adding reports and dashboards in microservices. We can also add a separate module for this purpose. Discuss how the reports and dashboards feature can be helpful in the microservices architecture.

Example: “Reports and dashboards help us with the monitoring and maintenance of a microservices product. For example, we can use them to identify the resources microservices exposes or to find the services that get affected by a change in a module. We can also refer to reports and dashboards while documenting an application or the process that it follows.”

8. How do you set up service discovery through the Netflix Eureka method?

Service discovery is the process through which one component discovers the network location of another component to communicate with it. Netflix Eureka is a hassle-free procedure for service discovery. It supports a large number of web applications and has a minimal impact on the application. Describe the steps involved in Eureka configuration, including client and server configurations.

Example: “Eureka uses a REST service, which is commonly known as Eureka Server. The services or the components that register with the Eureka Server for obtaining information are called Eureka Clients. We first require to configure a client. We can do this through the eureka-client.properties file. The server then uses this configuration to find other servers.”

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9. What do you understand by domain-driven design?

Explain the concept of domain-driven design (DDD). Consider including a simple example to display the clarity of your understanding.

Example: “Domain-driven design is a software development approach that seeks to solve the problems of a business by focusing on the domain logic of that business. For example, software for processing credit card applications needs to address the common and emerging issues of the credit card industry. The software needs to have several provisions like collecting customer data, validating creditworthiness and approving or rejecting an application. Such an approach to software development is called domain-driven design. It often requires collaboration with domain experts to understand the issues and the kind of solution a business domain requires.”

10. What aspects would you consider while performing a microservices security test?

In microservices, we are required to test the security of each component independently. Explain the different aspects of security testing, including code scanning, flexibility and adaptability.

Example: “In microservices, we are required to protect each component individually from unauthorised access. There are basically three aspects to security testing – code scanning, flexibility and adaptability. Code scanning ensures that each line of code is free from vulnerabilities and can be safely replicated. The security protocols require to be flexible enough so that we can adjust them to meet the specific requirements of the system. The security measures are also required to be adaptable to changes. For example, we are required to be able to update the security when we find new threats or breaches.”

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