Top 34 Microservices Interview Questions And Answers

Question 1

List down the advantages of Microservices Architecture

Accepted Answer

* **Independent Development**.	All microservices can be easily developed based on their individual functionality
* **Independent Deployment**.	Based on their services, they can be individually deployed in any application
* **Fault Isolation**.	Even if one service of the application does not work, the system still continues to function
* **Mixed Technology Stack**.	Different languages and technologies can be used to build different services of the same application
* **Granular Scaling**.	Individual components can scale as per need, there is no need to scale all components together

Question 2

Define Microservice Architecture

Accepted Answer

**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 3

Why Would You Opt For Microservices Architecture?

Accepted Answer

There are plenty of pros that are offered by Microservices architecture. Here are a few of them:

* Microservices can adapt easily to other frameworks or technologies.
* Failure of a single process does not affect the entire system.
* Provides support to big enterprises as well as small teams.
* Can be deployed independently and in relatively less time.

Question 4

What are smart endpoints and dumb pipes?

Accepted Answer

* **Smart endpoints** just meaning actual business rules and any other validations happens behind those endpoints which are not visible to anyone to the consumers of those endpoints think of it as a place where actual Magic happens.

* **Dumb pipelines** means any communication means where no further actions e.g validations are taken place, it simply carries the data across that particular channel and it may also be replaceable if need be. The infrastructure chosen is typically dumb (dumb as in acts as a message router only). It just means that routing is the only function the pipes should be doing.

Question 5

What is the difference between a proxy server and a reverse proxy server?

Accepted Answer

A simple definition would be: * **Forward Proxy**: Acting on behalf of a requestor (or service consumer) * **Reverse Proxy**: Acting on behalf of service/content producer. ![](https://i.stack.imgur.com/0qpxZ.png)
**Example:** Setting up a proxy in your browser so that Netflix doesn't know what country you're in is a _forward proxy_; an upstream service that directs an incoming request (perhaps you want to send one request to two servers) is a _reverse proxy_.

Question 6

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

Accepted Answer

*   **Monolithic Architecture** is similar to a big container wherein all the software components of an application are assembled together and tightly packaged.
*   A **Service-Oriented Architecture** is a collection of services which 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 standard patterns of orchestrating microservices?

Accepted Answer

As we start to model more and more complex logic, we have to deal with the problem of managing business processes that stretch across the boundary of individual services.

* With **orchestration**, we rely on a central brain to guide and drive the process, much like the conductor in an orchestra. The orchestration style corresponds more to the SOA idea of orchestration/task services. For example we could wrap the business flow in its own service. Where the proxy orchestrates the interaction between the microservices like shown in the below picture.

* With **choreography**, we inform each part of the system of its job, and let it work out the details, like dancers all find‐ ing their way and reacting to others around them in a ballet. The choreography style corresponds to the dumb pipes and smart endpoints mentioned by Martin Fowler's. That approach is also called the **domain approach** and is using domain events, where each service publish events regarding what have happened and other services can subscribe to those events.

Question 8

What are the challenges you face while working Microservice Architectures?

Accepted Answer

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

*   **Automate the Components**: Difficult to automate because there are a number of 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 each and every service for an error. It is essential to maintain centralized logging and dashboards to debug problems.

Question 9

What are main differences between Microservices and Monolithic Architecture?

Accepted Answer

**Microservices**
* Service Startup is fast
* Microservices are loosely coupled architecture.
* Changes done in a single data model does not affect other Microservices.
* Microservices  focuses  on products, not projects

**Monolithic Architecture**
* Service startup takes time
* Monolithic architecture is mostly tightly coupled.
* Any changes in the data model affect the entire database
* Monolithic put emphasize over the whole project

Question 10

Whether do you find GraphQL the right fit for designing _microservice_ architecture?

Accepted Answer

_GraphQL and microservices are a perfect fit_, because GraphQL hides the fact that you have a microservice architecture from the clients. From a backend perspective, you want to split everything into microservices, but from a frontend perspective, you would like all your data to come from a single API. Using GraphQL is the best way I know of that lets you do both. It lets you split up your backend into microservices, while still providing a single API to all your application, and allowing joins across data from different services.

![](https://ik.imagekit.io/jclivyrqwx/BrnFy_PBntiv2nD.png)

Top 34 Microservices Interview Questions

Define Microservice Architecture

List down the advantages of Microservices Architecture

Why Would You Opt For Microservices Architecture?

What Are The Fundamentals Of Microservices Design?

What are main differences between Microservices and Monolithic Architecture?

What is the difference between a proxy server and a reverse proxy server?

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

What are smart endpoints and dumb pipes?

What are the challenges you face while working Microservice Architectures?

What are the features of Microservices?

How does Microservice Architecture work?

Whether do you find GraphQL the right fit for designing microservice architecture?

What are the standard patterns of orchestrating microservices?

How can we perform Cross-Functional testing?

What is the role of an architect in Microservices architecture?

What is Materialized View pattern and when will you use it?

Mention some benefits and drawbacks of an API Gateway

What is Idempotence?

What do you understand by Distributed Transaction?

Explain what is the API Gateway pattern

What are the pros and cons of Microservice Architecture?

Can we create State Machines out of Microservices?

How should the various services share a common DB Schema and code?

What do you understand by Contract Testing?

What are Reactive Extensions in Microservices?

What is the difference between Cohesion and Coupling?

Why would one use sagas over 2PC and vice versa?

What is the most accepted transaction strategy for microservices?

Provide an example of "smart pipes" and "dumb endpoint"

Name the main differences between SOA and Microservices?

What Did The Law Stated By Melvin Conway Implied?

What is a Consumer-Driven Contract (CDC)?

How would you implement SSO for Microservice Architecture?

What does it mean that shifting to microservices creates a run-time problem?