complete list of Go (Golang) interview questions

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🧩 1. Basic Go Interview Questions

🔹 Language Basics

1. What are the main features of Go?
2. Why was Go developed, and what problems does it solve?
3. What are the advantages of using Go over Java, Python, or .NET?
4. Explain how Go handles memory management.
5. What is a package in Go?
6. How do you import packages in Go?
7. What is the purpose of the main package?
8. What is the difference between var, :=, and const?
9. What are Go data types?
10. What are slices in Go? How are they different from arrays?
11. How is string handling done in Go?
12. What are maps in Go? How do you iterate through a map?
13. What are structs?
14. What is an interface in Go?
15. What is the difference between value type and reference type in Go?

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⚙️ 2. Functions and Methods

1. How do you define a function in Go?
2. What are variadic functions?
3. Can functions return multiple values in Go?
4. What is a method receiver? Explain value vs pointer receivers.
5. Can you assign functions to variables in Go?
6. What are closures in Go?
7. What are higher-order functions?
8. How can you handle errors in Go functions?
9. What is defer used for?
10. What happens if multiple defer statements are used?

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🧵 3. Concurrency in Go (Important for Backend/Microservices)

1. What is a goroutine?
2. How is concurrency implemented in Go?
3. How do you start a goroutine?
4. What are channels in Go?
5. Difference between buffered and unbuffered channels?
6. How to prevent goroutine leaks?
7. What is the select statement used for?
8. What is the difference between concurrency and parallelism?
9. How to synchronize goroutines?
10. Explain sync.WaitGroup and sync.Mutex.
11. What are race conditions? How do you avoid them?
12. What is the purpose of context in Go?
13. How can you cancel a long-running goroutine using context?
14. Explain fan-in and fan-out patterns.
15. How would you implement a worker pool in Go?

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🧱 4. Error Handling

1. How does Go handle errors (since there are no exceptions)?
2. What is the error interface?
3. How can you create custom error types?
4. How do you wrap and unwrap errors in Go 1.13+?
5. Difference between panic, recover, and defer.

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🧰 5. Structs, Interfaces, and OOP Concepts

1. What is a struct in Go?
2. Can structs have methods?
3. How are interfaces different from structs?
4. What is interface embedding?
5. How do you check if a type implements an interface?
6. Can interfaces be empty? What is the use of interface{}?
7. How does Go achieve polymorphism?
8. What is dependency injection in Go?
9. Can Go support inheritance? If not, how do you achieve reuse?

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🌐 6. Go Modules and Packages

1. What is a Go module?
2. How do you initialize a module?
3. What is go.mod and go.sum?
4. How do you manage dependencies in Go?
5. What are the steps to build and run a Go module?
6. Difference between go install, go build, and go run.

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🗄️ 7. Go in Microservices and Backend Development

1. Why is Go popular for microservices?
2. How do you build a REST API in Go?
3. What are some popular Go frameworks for web development (e.g., Gin, Echo, Fiber)?
4. How do you handle JSON serialization/deserialization in Go?
5. How do you connect to databases in Go?
6. How do you handle configuration in Go microservices?
7. How do you use environment variables in Go?
8. How to handle logging and structured logs?
9. How to write unit tests in Go (testing package)?
10. How do you mock dependencies in Go tests?
11. How do you containerize a Go application with Docker?
12. How do you deploy Go microservices in Kubernetes?

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🧪 8. Testing and Benchmarking

1. How do you write test cases in Go?
2. How do you run tests using go test?
3. How do you write benchmark tests?
4. What is table-driven testing?
5. How do you use mock interfaces in tests?

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⚡ 9. Advanced Go Concepts

1. What is reflection in Go? When would you use it?
2. How do you use unsafe package?
3. What is iota in Go?
4. Explain type embedding.
5. How are generics handled in Go (1.18+)?
6. What are contexts and how are they used in microservices?
7. How does garbage collection work in Go?
8. What are Go routines scheduler and GOMAXPROCS?

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🧑‍💻 10. Scenario-Based Questions

1. How would you design a concurrent downloader in Go?
2. How would you implement a producer-consumer pattern?
3. How do you prevent data races in concurrent Go code?
4. How would you implement retry logic for failed API calls?
5. How to gracefully shut down a Go web server?
6. How to limit the number of concurrent goroutines?
7. How would you implement rate limiting in Go?

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🧠 11. Practical Code Questions

1. Write a Go function to reverse a string.
2. Write a Go function to check if a number is prime.
3. Implement a worker pool using goroutines and channels.
4. Implement a REST API endpoint with JSON response.
5. Parse JSON into struct and print specific fields.
6. Demonstrate use of sync.WaitGroup.
7. Implement retry logic using exponential backoff.
8. Create custom error type and handle it graceful