90+ Golang Developer Interview Questions and Answers

Yes, Go allows returning different data types. Go has OOP concepts and I have worked with microservices architecture.

• Go allows returning different data types using interfaces.

• I have worked with microservices architecture using Go and Docker.

• Go has OOP concepts like structs and methods.

Buffered channels have a fixed capacity while unbuffered channels have no capacity limit.

• Buffered channels allow sending multiple values without blocking until the buffer is full.

• Unbuffered channels block until the sender and receiver are both ready to communicate.

• Error handling methods include returning errors as values, using panic and recover, and logging errors.

• Errors can be solved by identifying the root cause, implementing a fix, and testing the solution.

Go is a fast, efficient, and easy-to-learn programming language with built-in concurrency features.

• Advantages of Go include its speed, simplicity, and concurrency features.

• Garbage collection is supported by other languages such as Java, Python, and Ruby.

• Go routines allow for easy and efficient concurrency without the need for traditional multithreading.

• Go is used by companies such as Google, Uber, and Dropbox for its performance and scalability.

Go does not have traditional OOP concepts like classes and inheritance, but it does support some OOP principles.

• Go supports encapsulation through the use of structs and methods.

• Polymorphism can be achieved through interfaces.

• Inheritance is not supported, but composition can be used instead.

• Go also supports abstraction through the use of interfaces and packages.

Questions on Docker, Kubernetes, unit testing, looping concepts, and Go path and root.

• Docker is a containerization platform used for packaging and deploying applications. Kubernetes is a container orchestration tool used for managing containerized applications.

• Unit testing in Go can be done using the built-in testing package and the 'go test' command.

• Go has only one looping concept, the 'for' loop.

• Go path is the location where Go packages are installed and Go root is the loca...read more

Questions on Go programming language concepts

• Empty interface is an interface with no methods. Empty struct is a struct with no fields.

• Array has fixed size, slice is dynamic. Array is passed by value, slice is passed by reference.

• Function is standalone, method is associated with a type. Method has a receiver, function does not.

REST API can be implemented in both Golang and other languages using HTTP methods and JSON data format.

• In Golang, we can use third-party packages like Gorilla Mux and net/http to create REST APIs.

• We can define routes and handlers for each HTTP method like GET, POST, PUT, DELETE.

• We can use JSON encoding and decoding to send and receive data in REST API calls.

• In other languages, we can use frameworks like Flask in Python, Express in Node.js to create REST APIs.

• We can use tools ...read more

Types of channels in Go and their use cases

• Buffered channels: Allow multiple senders to send data without blocking until the buffer is full

• Unbuffered channels: Synchronize goroutines by blocking sender until receiver is ready

• Bidirectional channels: Allow both sending and receiving data

• Receive-only channels: Restrict channel to only receive data

• Send-only channels: Restrict channel to only send data

Channels are a way for goroutines to communicate. Buffered channels have a capacity while unbuffered channels do not.

• Unbuffered channels block until a sender and receiver are ready to communicate

• Buffered channels allow for asynchronous communication up to a certain capacity

• Channels are typed, meaning they can only send and receive values of a specific type

Questions related to Go programming language concepts and design patterns.

• Pointer is a variable that stores the memory address of another variable, while slice is a reference to an underlying array.

• Arrays have a fixed size, while slices are dynamic and can grow or shrink.

• Maps are key-value pairs, used to store and retrieve data based on a unique key.

• Bridge pattern is used to separate an abstraction from its implementation, allowing them to vary independently.

• Singleton pattern...read more

I handle errors by using error handling mechanisms like try-catch blocks and returning error codes or messages.

• Use try-catch blocks to catch and handle errors

• Return error codes or messages to indicate the type of error

• Implement error handling mechanisms like panic and recover in Go

To create a package, define a new directory and add a file with package name and functions. My project is a web scraper.

• Create a new directory with package name

• Add a file with package name and functions

• Import the package in main program

• Use the functions in the package

• Example: package name - scraper, functions - scrapeWebsite(url string) string

• Example usage: import 'scraper', scraper.scrapeWebsite('https://example.com')

A channel is a way for goroutines to communicate with each other and synchronize their execution.

• Channels are typed and can only transmit values of that type.

• There are two types of channels: buffered and unbuffered.

• Unbuffered channels block until a sender and receiver are ready to communicate.

• Buffered channels have a fixed capacity and can transmit values without blocking until the buffer is full.

• Channels can be used to implement various synchronization patterns such as worke...read more

A worker pool in Golang efficiently manages concurrent tasks using goroutines and channels.

• Define a worker function that processes tasks from a channel.

• Create a pool of workers by launching multiple goroutines.

• Use a channel to send tasks to workers and another to receive results.

• Example: Use 'sync.WaitGroup' to wait for all workers to finish.

Concurrency is the ability to run multiple tasks simultaneously, achieving parallelism.

• Go uses goroutines to achieve concurrency

• Goroutines are lightweight threads managed by the Go runtime

• Concurrency in Go is achieved using channels for communication between goroutines

Goroutines are lightweight threads of execution in Go that allow for concurrent programming.

• Goroutines are created using the 'go' keyword followed by a function call.

• Concurrency is the ability to run multiple tasks simultaneously, while parallelism is the ability to run multiple tasks at the same time.

• Goroutines can communicate with each other using channels.

• Example: go func() { fmt.Println('Hello, world!') }()

• Example: c := make(chan int); go func() { c <- 1 }(); x := <-c; fm...read more

gRPC is a high-performance, open-source RPC framework developed by Google.

• gRPC stands for Google Remote Procedure Call.

• It uses HTTP/2 for transport, Protocol Buffers for serialization, and supports multiple programming languages.

• gRPC is commonly used for building efficient and scalable microservices.

• It allows for bidirectional streaming and authentication features.

• Examples of companies using gRPC include Google, Netflix, and Square.

The output is calculated using a mathematical formula based on the input number.

• The formula to calculate the output is: output = (input^2) + (input * 2)

• For example, for input 3: output = (3^2) + (3 * 2) = 9 + 6 = 15

• For example, for input 4: output = (4^2) + (4 * 2) = 16 + 8 = 24

Efficiently process large amounts of data by using parallel processing, optimizing algorithms, and utilizing data structures.

• Utilize parallel processing techniques such as goroutines in Golang to process data concurrently.

• Optimize algorithms to reduce time complexity and improve processing speed.

• Use efficient data structures like maps, slices, and channels to store and manipulate data.

• Consider using caching mechanisms to reduce the need for repeated data processing.

• Implement ...read more

Const variables are immutable and can be used to declare values that won't change during runtime. String replace replaces a substring with another in a string.

• Const variables are declared using the 'const' keyword and cannot be reassigned.

• String replace can be used to replace a substring with another in a string.

• Example: const pi = 3.14; str := 'Hello World'; newStr := strings.Replace(str, 'World', 'Golang', -1);

• Example: const arr = [3]string{'apple', 'banana', 'orange'}; new...read more

Singleton is a creational design pattern that ensures a class has only one instance and provides a global point of access to it.

• Singleton pattern restricts the instantiation of a class to one object.

• It is useful when exactly one object is needed to coordinate actions across the system.

• Singleton pattern can be implemented using lazy initialization or eager initialization.

• Example: Database connection, Logger, Configuration settings.

• Singleton pattern can be implemented in Go usi...read more

Microservices are small, independent services while monolithic is a single, large application.

• Microservices are loosely coupled and can be developed and deployed independently.

• Monolithic applications are tightly coupled and require a complete redeployment for any changes.

• Microservices allow for better scalability and fault tolerance.

• Monolithic applications are easier to develop and test.

• Examples of microservices include Netflix, Amazon, and Uber.

• Examples of monolithic applica...read more

The use case of defer in a project and a logic to reverse an array of strings.

• Defer is used to ensure that a function call is performed later in a program's execution.

• It is commonly used to close resources, unlock mutexes, or log the execution time.

• To reverse an array of strings, iterate from both ends and swap the elements until the middle is reached.

I have handled multi threading by using goroutines and channels in Golang.

• Used goroutines to run concurrent tasks

• Used channels to communicate between goroutines

• Avoided race conditions by using mutexes or sync package

Sharding is a database architecture pattern that splits data across multiple servers to improve performance and scalability.

• Identify the sharding key: Choose a key that will determine how data is distributed (e.g., user ID, geographic location).

• Design the shard architecture: Decide on the number of shards and how they will be managed (e.g., horizontal vs. vertical sharding).

• Implement data distribution: Write logic to route queries to the appropriate shard based on the shardin...read more

I have worked on various projects, including a web application for managing employee data.

• I follow the Arrange-Act-Assert pattern for unit testing

• I use testing frameworks like GoConvey and testify

• I write test cases for both positive and negative scenarios

• I use mocks and stubs to isolate dependencies

• I aim for high code coverage to ensure thorough testing

Implementing an interface with methods in Go

• Define an interface with method signatures

• Create a struct that implements the interface methods

• Use the 'implements' keyword to associate the struct with the interface

• Call the interface methods on the struct instance