Understanding Microservice Architecture

Microservices - also known as the microservice architecture - is an architectural style that structures an application as a collection of services that are

• Highly maintainable and testable
• Loosely coupled
• Independently deployable
• Organized around business capabilities
• Owned by a small team

The microservice architecture enables the rapid, frequent, and reliable delivery of large, complex applications. It also enables an organization to evolve its technology stack.

Hence, to help you prepare for your interviews, I have come up with Microservices Interview Questions and Answers.

Question 1. What do you know about Microservices?

• Microservices, aka microservice architecture, is an architectural style that structures an application as a collection of small autonomous services, modeled around a business domain.

Question 2. List down the advantages of Microservices Architecture.

Question 3. What are the features of Microservices?

• Decoupling – Services within a system are largely decoupled. So the application as a whole can be easily built, altered, and scaled
• Componentization – Microservices are treated as independent components that can be easily replaced and upgraded
• Business Capabilities – Microservices are very simple and focus on a single capability
• Autonomy – Developers and teams can work independently of each other, thus increasing speed
• Continuous Delivery – Allows frequent releases of software, through systematic automation of software creation, testing, and approval
• Responsibility – Microservices do not focus on applications as projects. Instead, they treat applications as products for which they are responsible
• Decentralized Governance – The focus is on using the right tool for the right job. That means there is no standardized pattern or any technology pattern. Developers have the freedom to choose the best useful tools to solve their problems
• Agility – Microservices support agile development. Any new feature can be quickly developed and discarded again

Question 4. What are the best practices to design Microservices?

1.    Separate data store for each microservice

2.    Keep code at a similar level of maturity

3.    Separate build for each microservice

4.    Deploy into containers

5.    Treat server as stateless  

Question 5. What are the components of Microservice Architecture?

• Clients – Different users from various devices send requests.
• Identity Providers – Authenticates user or client identities and issues security tokens.
• API Gateway – Handles client requests.
• Static Content – Houses all the content of the system.
• Management – Balances services on nodes and identifies failures.
• Service Discovery – A guide to find the route of communication between microservices.
• Content Delivery Networks – Distributed network of proxy servers and their data centers.
• Remote Service – Enables the remote access information that resides on a network of IT devices.

Question 6. What is the difference between Monolithic, SOA, and Microservices Architecture?

• Monolithic Architecture is similar to a big container wherein all the software components of an application are assembled and tightly packaged.
• A Service-Oriented Architecture is a collection of services that communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity.
• Microservice Architecture is an architectural style that structures an application as a collection of small autonomous services, modeled around a business domain.

Question 7. What are the challenges you face while working in Microservice Architectures?

Developing several smaller microservices sounds easy, but the challenges often faced while developing them are as follows.

• Automate the Components: Difficult to automate because there are several smaller components. So for each component, we have to follow the stages of Build, Deploy, and, Monitor.
• Perceptibility: Maintaining a large number of components together becomes difficult to deploy, maintain, monitor, and identify problems. It requires great perceptibility around all the components.
• Configuration Management: Maintaining the configurations for the components across the various environments becomes tough sometimes.
• Debugging: Difficult to find out every service for an error. It is essential to maintain centralized logging and dashboards to debug problems.

Question 8. What Is Spring Cloud?

Probably, the first microservices interview question that you may encounter. Spring Cloud in Microservices, is a system that provides integration with external systems. It is a short-lived framework that builds an application in a fast manner. Being associated with the finite amount of data processing, it plays a very important role in Microservice architecture.

For typical use cases, Spring cloud provides some out of the box experience and a set of extensive features mentioned-below:

• Versioned and distributed configuration
• Discovery of the service registration
• Service to service calls
• Routing
• Circuit breakers and load balancing
• Cluster state and leadership election
• Global locks and distributed messaging

Question 9. What Is Spring Boot?

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

With the new functionalities that have been added, Spring got 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. Explaining by a real-time example is better while answering this common microservices interview question. If you are cooking a dish, the ingredients can be considered to be Spring. While Spring Boot is the completely cooked recipe.

Question 10. What Do You Mean by End-To-End Testing of Microservices?

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