Top 25 Microservices Interview Questions and Answers in 2023

Microservices Interview Questions and Answers

Microservices, commonly known as Microservices architecture, offers software developers and development teams an easier way of building large applications, i.e., several small functional modules. It is used by most Agile teams, which explains its popularity. If you are applying for a Microservices-related job, you need the right level of preparation ahead of your interview.

This article will look at some of the questions you should expect in your upcoming Microservices Interview. We are interested in ensuring that you come out of the interview successfully; therefore, we have researched and come up with some of the most asked questions. Take a look at the following:

1. Microservices Are Made Up Of Several Components. Mention Them

Microservices have six main components. They include cloud infrastructure, service delivery, API gateway, enterprise service bus, infrastructure as code conception popularly known as IAC, containers, clustering, and orchestration, which are normally grouped as one.

2. What Are The Main Features Of Microservices?

Microservices have various features that help DevOps teams in their software development cycles. They include decoupling, which helps in easy construction, alteration, and scalability of applications; team autonomy which empowers every developer to work independently of the other; continuous delivery that allows systematic software development through automation; agility, thus allowing the expeditious creation and elimination of features and decentralized governance that allows developers to pick the best tools to solve different problems. Microservices are also quite simple and only focus on a singular service. Lastly, they have a feature, which means that the independent components can be easily upgraded and exchanged.

3. Mention All The Benefits Of Microservices.

The role microservices play in the software development cycle brings many advantages worth exploring. Microservices ensure better communication between different stakeholders, promotes a higher degree of scalability and agility, and allow the deployment of demand services on several servers. Other benefits are: it offers independently managed services that allow for simpler maintenance and debugging, has fewer dependencies, makes testing easy, and caters to small development teams.

4. What Are The Shortcomings Of Microservices?

Despite its benefits, this SDLC approach comes with some drawbacks. It is quite complex, so testing and monitoring are challenging. Also, given that it is mostly used in agile settings, an organization must have the proper cultural culture. Other drawbacks are: it needs lots of pre-planning, the development team or organization should have a cultural shift, it is difficult to maintain the network, it is expensive compared to other options, it comes with security complications, and development can be quite complex.

5. How Does Microservices Architecture Work?

The working mechanism of Microservices architecture depends on several components. The first component is the client, the user sending requests from different devices. The second is the identity provider, whose role is to validate a user’s or a given client’s identity before issuing a security token. The API gateway is revived and handles client requests while the static content stores all the system’s contents. The fifth component is management, where services are usually balanced on nodes. It also identifies different failures. Microservices also have service delivery discovery which discovers all the communication routes in the systems. The last two components are a content delivery network made up of proxy servers and the respective data centers and then remote service that offers remote access to data or the information found on networked devices and computers.

6. Differentiate Between The SOA, Monolithic, And Microservices Architecture

Monolithic has the simplest architecture. It is more of a big container, meaning that all the software components of a given application are usually tightly grouped. It is a one-code base and is generally built as one single but a large system 

SOA, fully known as service-oriented architecture, consists of various services communicating with one another. Communication can range from simple data exchange to coordination of activities.

Lastly, in the Microservice architecture l, applications ate structured in clusters of small autonomous services. It allows the independent deployment of all functional modules to achieve different business goals. They also use standard protocols to communicate with each other.

7. Differentiate Spring Cloud And Spring Boot

Spring Boot offers developers a platform for creating independent production-grade spring applications. This Java-based and open-source network saves developers time and further increases productivity. On the other hand, the spring cloud integrates with external systems. This system is quite short-lived but helps in the quick building of applications. It is an important feature in the Microservices architecture given its prowess in data processing.

8. Mention The Different Issues Handled By The Spring Cloud

The spring cloud is an important system in the Microservices architecture because it can handle several issues such as load balancing, service delivery, redundancy, and performance issues. In handling service delivery issues, it allows processes and services to communicate and locate one another easily. It attempts to solve all the operational overheads that may affect performance on performance issues.

9. What Are The Basic Characteristics Of The Microservice Design?

The Microservices architecture is usually based on business capabilities, meaning that all the services are divided and organized around the capabilities. It also dictates that products belong to the team handling it and offer decentralized data management, meaning that each service is empowered to manage its data separately. Microservices also have an automated infrastructure, meaning that the services can be independently deployed given that they ate completely. Other features include a design for failure, decentralized governance, and essential messaging frameworks.

10. Define Cohesion And Coupling

Coupling and cohesion are common terms in Microservices. Cohesion is the relationship between two or more elements in a given module charged with the same function. Modules with high cohesion are usually empowered to perform efficiently without the assistance of other modules. A module with high cohesion is usually more functional. On the other hand, coupling refers to the relationship between two software modules and their interdependence. Highly coupled modules are usually heavily interdependent. The best type of coupling is loose coupling which happens via interfaces.

11. There Are Several Challenges One Is Bound To Face When Using Microservices. Mention Them

Microservices is not all rosy as it also comes with a number of challenges, either functional or technical. For functional challenges, its architecture requires heavy infrastructural setup, calls for heavy investment and requires detailed planning for handling and managing operations overhead. Most of the challenges ate technical. Therefore, one should expect a high level of interdependence and heavy involvement given that this is a distributed system, early preparation for operations overhead and deployment, testing, and debugging challenges. Other technical challenges include the need for highly skilled handlers given that this is a heterogeneously distributed system and the difficulty in automation brought about by the several small components.

12. You Have Mentioned That There Is A High Level Of Interdependence In Microservices. How Do These Services Communicate With One Another?

Microservices constantly communicate through three main ways: web sockets used for streaming, broker or server programs that utilize technical routing algorithms, and HTTP/ REST with JSON. They can also perform the request-response operation via a binary protocol. Other proven means include backend as a service that will automate the entire backend. Additionally, one can use RabbitMQ as a message blocker.

13. Differentiate Between Semantic And Continuous Monitoring

Also known as the synthetic monitoring method, semantic monitoring relies on automated tests and application monitoring for error identification in business processes. It, therefore, delves into the transaction performance, overall performance of the application, and service availability to identify different performance issues. It can also catch bugs and, in return, boost performance. On the other hand, continuous monitoring identifies compliance and risk issues in a given company’s operational and financial environment. It is, therefore, a collection of systems, processes, and people charged with efficient operations.

14. What Is Domain-Driven Design

 Domain-Driven Design, popularly known as DDD, is an architectural style built on the principles and approaches of Object-Oriented Analysis Design. Professionals skillfully model the business domain in software without considering the working mechanism of the system. However, the related components of the software system are interconnected into an evolving system, permitting the development of larger and more complex systems. The domain-driven design is based on three main principles: concentration on the core domain and logic, analysis of domain models to identify complex designs, and regular collaboration with domain experts for improvement of application models.

15. Why Do You Think Reports And Dashboards Are Important In Microservices?

Reports and dashboards come in handy in system monitoring, which explains why they are important components in Microservices. They help determine the resources to be supported by different Microservices and the services affected by changes to components. They also allow easier access to documentation when necessary, help determine every component’s level of compliance and maturity, and, lastly, help review the deployed component versions. Their use should therefore be encouraged in Microservices owing to these advantages.

16. There Are Three Main Types Of Tests Used In Microservices. Mention Them

Microservices testing is a complicated but important aspect, given the interdependence of these services. Tests are generally grouped depending on their level. At the top of the pyramid, we have system tests, integration tests, and unit tests. The unit tests at the bottom of the pyramid deal with technology-related components and issues. It is similar to performance testing, which is all automated processes.

The middle-level or integration tests consist of exploratory tests such as usability tests. In contrast, the top-level tests at the top of the pyramid consist of a small collection of acceptance tests. They are used to understand and verify software features by developers.

17. While Still On Tests, We Have Mike Cohn’s Test Pyramid. Can You Please Explain What It Is?

Mike Cohn’s Test Pyramid offers information on the different types of automated tests that serve a purpose in software development. This pyramid maximizes automation in all testing levels, including UI, service, and unit testing. It also dictates that unit tests happen faster and are more isolated while their counterparts, UI tests found at the top, take time and are less isolated. They are instead centered around integration.

The pyramid demands that the first layer have a higher number of tests while fewer tests should be done at the service layer. 

18. What Are The Roles Of Containers In Microservices?

Like many interdependent systems, Microservices has containers, which are used to allocate and share resources. These useful technologies provide an effective and easy method for micro-service-based management applications for independent development and deployment. One can easily use Docker to highlight a Microservice and its dependencies on a container image. These images save teams from extra work and effort as they can be furnished in roll-on-demand instances.

19. One Of The Most Important Tools Used In Microservices Is Docker. Can You Explain Its Use?

Like many other frameworks, systems, and units, Microservices has several important tools that allow for efficient operation and improved performance. Docker is one of the most common and important tools because it offers a container environment for hosting applications. It tightly packages the applications and their dependencies, giving rise to units called containers. All the container’s packages using Docker are therefore referred to as Docker containers. This tool helps in containerization and easier management of Microservices.

20. Can You Mention The Cons Of The Microservices Architecture?

There are several shortcomings of the Microservices Architecture, which have been noted by teams all over the world. It increases troubleshooting challenges, which can be highly frustrating. It also leads to increased delay owing to remote calls and makes it difficult to maintain the safety of transactions. Other cons include increased configuration and operational efforts, difficulty in coding between services, and lastly, it makes tracking data across boundaries hard. All in all, the advantages outweigh the cons.

21. Differentiate SOA And Microservices

The service-oriented architecture, popularly known as SOA, comes with several features that are different from Microservices. It mainly focuses on the reuse of business functionalities, has a share-as-much-as-possible architecture approach, comes with shared governance and standards, supports several message protocols, maximizes the reusability of application services, and requires a systematic change for monolith modification, and is multi-threaded. Microservices, on the other hand, mainly focus on bounded context, follows a share as little as possible architecture approach, focus more on collaboration and optional freedoms, have lightweight messaging protocols such as HTTP, focus more on decoupling requires a systematic change in the creation of new services and is single-threaded.

22. Define REST And Its Relation To Microservices

REST is a popular medium used in several applications such as MVC for business data servicing, web applications, and API design. It can be used to build or implement Microservices through the REST over HTTP approach, making it one of the many ways of Microservices implementation. This is because Microservices have system components that can be independently deployed, built, and scaled. Using REST over HTTP is one of the best practices of Microservices when one aims to build a resilient application.

23. Define Distributed Transactions And Idempotence

Distributed Transactions occur when single events lead to the mutation of two or multiple data sources unable to get atomically committed. Distributed Transactions are quite complex in Microservices, where every service is a work unit. These services are also required to work interdependently for the business’s overall success.

Idempotence is the ability to perform an operation twice but end up with the same results, suggesting that it had been done only once. It is normally used at the data source or remote service when instruction is received more than once.

24. Define Contract And End-To-End Micro Testing In Microservices

Martin Flower coined contract testing. It targets an external service’s boundary to verify if it is in line with the contract a consuming service expects. However, it does not focus much on the service’s behavior but instead concerns itself with the service calls input and output service calls, confirming whether they have the response latency, the necessary attributes, and the right throughout. On the other hand, end-to-end testing serves as a means of validating that all the processes in a given workflow are highly functional. These tests are normally done periodically.

25. The Microservices Architecture Requires An Architect. CAN You Mention The Roles Played By The Architect?

An architect plays five main roles in Microservices. They work closely with the development team to have an in-depth understanding of the challenges experienced in their daily lives, offer technical guidance so that that the development team follows all the principles of Microservices, and decide on component zoning by ensuring that every component is mutually cohesive, make decisions in the overall layout of software systems and lastly, recommend tools and technologies that can benefit the team.


These 25 questions should be handy as you prepare for your upcoming Microservices Interview. Keep in mind that potential employers need highly skilled and confident employees. Therefore, try as much as possible to cover all the technical aspects of your Microservices-related job before attending the interview.

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