Go Interview Questions

Learning without testing your knowledge can lead to wrong perception about your expertise level. This article provides you a list of questions for you to evaluate yourself easier.

Go Questions

1. Basic

• What is Go?
• Why should you learn Go?
• What is Go suitable for?
• What are the advantages and disadvantages of Go?
• How Go is different from the programming languages that you have used? (Java, C/C++, Python, Rust, NodeJS, JavaScript)

2. Array and Slice

• What are the differences between array and slice?
• What are the differences between slice and link list?
• How re- slicing process of a slice happen under the hood?
• Can you modify array length? Can you append new item into an array?
• Explain how different between array/slice in Go and array in C/Java?

3. String

• How is string in Go constructed? And what is the different between string in Go with other programming languages?
• What is string literal? How is it done in Go?
• Explain how you can write multi-line strings in GO?

4. Goroutine

• What are the difference between goroutine and OS thread?
• Explain what is go routine in GO? How you can stop go routine?
• What is a worker pool? And how to do that in Go?
• How to stop a worker pool?
• What is fan-in, fan-out?
• What is sync.WaitGroup used for?
• What are the differences between sync.Mutex and semaphore?
• What are the differences between concurrency and parallelism?
• What are the differences between sharing by communicate vs communicate by sharing?
• What is channel? How does it work? What is it used for?
• What is context? What is it used for?
• Have you used goroutine in your application? Describe it.
• Why goroutine is better than thread?
• What is goroutine leak in Go? How to prevent it?

5. Interface

• Explain Interface in Go
• How interface in Go different from interface in other languages?
• When should you use interface?
• How did you use interface in your previous project?

6. Other General Questions:

• Does Go pass by value or pass by references? What are the differences?
• What is Go run time?
• How does garbage collector work in Go?
• What is inside the interface{}?
• How to handle gracefully shutdown in Go?
• Why would you prefer to use an empty struct{} ? Provide some examples of the good use of the empty struct{} .
• How do you compare two structs? What about two interfaces? Provide examples.
• How do you implement stack and queue in Go? Provide an example.
• What is type assertion and how is it done in Go?
• How type conversion is done in Go?
• What is the difference, if any, in the following two slice declarations, and which one is more preferable? var a []int and a := []int{}

Real Experiences Questions

1. General:

• How did you structure your last project in Go? What are the advantages and disadvantages of it?

2. Config

• How did you manage configurations of your services in Go?
• What kind of libraries did you use for configuration management in Go? Compare them.
• How did you manage configurations of your services in Docker, OpenShift, Kubenetes environment?

3. HTTP

• Have you ever used any framework for working with HTTP in Go? Compare it with native HTTP library provided by Go.
• What is middleware? Have you ever written one?

4. Logging

• Explain how did you implement logging component in your last application with Go?
• Did you use any libraries for logging in Go? Explain how did you use it and compare with native logging library.
• How did you organize logging in containerize environment like Docker, Kubernetes, OpenShift where you have a lot of instances running at the same time?

5. Deployment:

• How did you deploy your application?
• Have you ever used Docker or any containerize technology for deployment? Describes it.
• Have you ever written Docker file? Describes it?

6. Database:

• Have you ever used MongoDB? Explain in detail what did you use it for?
• Explain what are the differences between NoSQL and SQL? When should you use NoSQL and when not to?
• What library did you use to interact with MongoDB in Go? Compare it with other libraries.
• How big your data is?
• How did you scale your MongoDB for performance?

7. Search Engine:

• What did you use Elasticsearch for?
• When should you use Elasticsearch and when should you use MongoDB?
• What library did you use to interact with Elasticsearch in Go?
• How did you handle a lot of indexing in high performance application?
• Do you know bulk processor? Did you use it? How does it work?

8. Message queue:

• Have you ever used any message queue technology? Describe how did you use it.
• Have you ever used Kafka? How is it used in your application? And why did you choose it?
• When should you use message queue? Give some example.

9. Performance

• How many query/second of your application?
• How can you measure performance of your application?
• How did you scale up your application?