80+ 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

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

defer in Go is used to delay the execution of a function until the surrounding function returns.

• Defer is used to ensure that a function call is performed at the end of the surrounding function, regardless of where the defer statement is located.

• If there are multiple defers in a function, they will be executed in Last In, First Out (LIFO) order.

• Example: func exampleFunc() { defer fmt.Println('First defer'); defer fmt.Println('Second defer'); } // Output: Second defer First def...read more

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

Complicity faced in project: Handling concurrent requests and ensuring data consistency

• Implemented mutex locks to prevent race conditions

• Used channels to coordinate communication between goroutines

• Ensured atomicity of operations on shared data

• Implemented retry mechanisms to handle failed requests

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

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

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

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

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')

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.

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

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

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

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 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

Concurrency is the ability of a program to execute multiple tasks simultaneously. Race condition occurs when multiple threads access shared data and try to change it at the same time.

• Concurrency allows multiple tasks to run in parallel, improving performance and efficiency.

• Race condition happens when multiple threads access and modify shared data without proper synchronization.

• To prevent race conditions, synchronization mechanisms like mutexes or channels can be used.

• Example:...read more

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

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

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

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

• They are executed concurrently with other goroutines and can communicate using channels.

• Switch statements can be used to control the flow of execution between multiple goroutines.

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

• Example: select { case msg := <-ch: fmt.Println(msg) }

Slice is a dynamically-sized, flexible view of elements in an array. Concurrency is the ability to run multiple tasks at the same time, while parallelism is the actual execution of multiple tasks simultaneously.

• Slice in Go is a reference to a portion of an array. It allows for dynamic resizing and manipulation of elements.

• Example: var s []int = make([]int, 5) // creates a slice of length 5

• Interfaces in Go define a set of methods that a type must implement. They allow for poly...read more

A program in Go that demonstrates the use of goroutines, channels, and a wait group.

• Create a goroutine that performs a task concurrently.

• Use channels to communicate between goroutines.

• Use a wait group to synchronize the completion of goroutines.

• Example: Calculate the sum of numbers using multiple goroutines and a channel.

SOLID is an acronym for five principles of object-oriented programming design.

• S - Single Responsibility Principle: A class should have only one reason to change.

• O - Open/Closed Principle: Software entities should be open for extension but closed for modification.

• L - Liskov Substitution Principle: Subtypes must be substitutable for their base types.

• I - Interface Segregation Principle: Clients should not be forced to depend on interfaces they do not use.

• D - Dependency Inversion...read more

Buffered channels allow multiple senders to send data without blocking, while unbuffered channels block until data is received.

• Buffered channels have a fixed capacity and can store multiple values until they are received

• Unbuffered channels have no capacity and block until a receiver is ready to receive the data

• Buffered channels are useful for improving performance in cases where there are multiple senders

• Unbuffered channels are useful for synchronization between goroutines

• Exa...read more

Goroutines are used in projects to achieve concurrent execution. Popular project frameworks include Gin, Echo, and Revel.

• Goroutines are lightweight threads that allow concurrent execution in Go.

• They are commonly used for tasks like handling multiple HTTP requests simultaneously.

• Gin, Echo, and Revel are popular project frameworks that support goroutines for building web applications.

Go is a statically typed, compiled language with a focus on concurrency and simplicity.

• Go has a simpler syntax compared to other languages like Java or C++

• Go has built-in concurrency support with goroutines and channels

• Go has a garbage collector that automatically manages memory

• Go compiles to machine code, making it faster than interpreted languages like Python

• Go has a standard library that includes many useful packages for networking, cryptography, and more

Use go routines and channels to print numbers 1 to 10

• Create a channel to communicate between go routines

• Use a for loop to create 10 go routines, each printing a number

• Send the numbers through the channel and print them in the main routine

Using goroutine to print even and odd numbers upto 100

• Create two goroutines, one for printing even numbers and one for printing odd numbers

• Use a channel to communicate between the goroutines

• Loop through numbers 1 to 100 and send them to the appropriate goroutine for printing

There are three tokens generated in JWT: Header, Payload, and Signature.

• Header token contains metadata about the type of token and the hashing algorithm used.

• Payload token contains the claims or data being transmitted.

• Signature token is created by combining the encoded header, encoded payload, a secret key, and the hashing algorithm.

A map is a built-in data structure in Golang that allows you to store key-value pairs.

• Maps are unordered collections of key-value pairs.

• Keys in a map must be unique.

• Maps are useful for efficient lookup and retrieval of values based on their keys.

• You can add, update, and delete key-value pairs in a map.

• Example: map[string]int{"apple": 5, "banana": 3}

Definition of struct, interface, method, and function.

• Struct is a composite data type that groups together zero or more values with different types.

• Interface is a collection of method signatures that a type can implement.

• Method is a function that has a receiver argument.

• Function is a block of code that performs a specific task and can be called from other parts of the program.

Designing Uber involves creating a scalable and efficient ride-sharing platform.

• Implement a user authentication system for drivers and passengers.

• Develop a real-time location tracking feature for drivers and passengers.

• Design a matching algorithm to pair drivers with passengers based on location and availability.

• Create a payment system for seamless transactions between drivers and passengers.

Use SQL query with WHERE clause to filter employees coming to office.

• Use SELECT statement to retrieve data from the database.

• Use WHERE clause to filter employees based on coming to office.

• Consider using a column in the database that indicates whether an employee is coming to office or not.

Go supports object-oriented programming principles through struct types and methods.

• Go uses struct types to define objects with fields and methods.

• Methods can be defined on struct types to provide behavior to objects.

• Go does not have classes like traditional OOP languages, but it supports encapsulation, inheritance, and polymorphism through struct embedding and interfaces.

Arrays are fixed-size collections of elements of the same type, while slices are dynamic arrays with a flexible size.

• Arrays have a fixed size determined at compile time.

• Slices are dynamic arrays that can grow or shrink.

• Arrays and slices are both zero-indexed.

• Arrays are passed by value, while slices are passed by reference.

• Example: var arr [3]string = [3]string{"apple", "banana", "orange"}

• Example: var slice []string = []string{"apple", "banana", "orange"}

Kubernetes controller manages the state of a cluster by continuously monitoring and reconciling desired state with current state.

• Controllers are responsible for maintaining the desired state of the system

• They monitor the current state of the system and compare it with the desired state

• If there is a difference, the controller takes action to reconcile the two states

• Controllers can be built-in or custom

• Examples of built-in controllers include Deployment, ReplicaSet, and Statefu...read more

Pointers are variables that store the memory address of another variable. Channels are used for communication between goroutines.

• Pointers allow direct access to memory, making it possible to modify values at a specific address.

• Channels are used to pass data between goroutines, allowing for synchronization and communication.

• Pointers can be used to pass large data structures to functions without copying the entire structure.

• Channels can be used to implement a producer-consumer ...read more

Concurrency is about dealing with multiple tasks at the same time, while parallelism is about executing multiple tasks simultaneously.

• Concurrency is about structure, while parallelism is about execution.

• Concurrency can be achieved with a single core processor, while parallelism requires multiple cores.

• An example of concurrency is a single-threaded program that switches between tasks, while an example of parallelism is a multi-threaded program where tasks run simultaneously.

Implement a stack using the given structure.

• Create a struct with an array to store the stack elements and an index to keep track of the top element

• Implement functions like push, pop, and peek to manipulate the stack

• Ensure to handle stack overflow and underflow cases

Using Go routines to generate Fibonacci series

• Create a function to generate Fibonacci numbers using recursion

• Use Go routines to generate Fibonacci numbers concurrently

• Use channels to communicate between Go routines