Interview questions are nothing like what you’re going to face in your day-to-day job. While every company will ask you different questions, the main gist remains the same. How well are you prepared.
You can view technical interviews as entry exams. The job description? Exam syllabus. To be fair, put yourself in the recruiter’s shoes. They receive many requests and have to find someone suitable in the shortest and most efficient manner. Are technical interviews the ‘best’ way to do it? Probably not. But they yield consistent results.

So, the natural thing to do is to study beforehand, practice your responses and gain experience.
In this post, I’m going to gather some questions you may be asked for mid-level Go backend developer positions. It is by no means not exhaustive and questions are mostly found online. I haven’t included answers as well. My thinking is: gain easy, lose easy. You need to know these questions and their respectable answers by heart. In my experience, the best approach is for you to go in some trouble into finding answers. Search online, ask your coworkers, reflect on your response, write down your points and remarks.

Go Programming Language Logo

Go

  • Explain the difference between Goroutines and Threads?
  • How does concurrency differ from parallelism?
  • When to use defer statement? How and in what order does it get executed?
  • Tell me the differences between buffered and unbuffered channels.
  • Talk about a challenge you had and how did you manage to solve it
  • When to panic? How to deal with it?
  • What is the purpose of the context package in Go, and how is it used in a web application?
  • How does garbage collection work in Go? Talk about its algorithm, GC cycles, how and when to tweak it.
  • What are the differences between sync.Mutex and sync.RWMutex?
  • How do you prevent race conditions in Go?
  • What are the main advantages of Go that makes you use it over other languages?
  • What are your biggest criticisms of Go? How you mitigate with them.
  • Tell me the differences between inheritance and composition.
  • Let’s have a talk about concurrency patterns in Go, such as the actor model or other patterns used in distributed systems.
  • What are the differences between arrays and slices in Go?
  • How to use a goroutine pool?
  • What do you consider to be good patterns for testing?
  • Have you ever encountered a concurrency bug? Explain more.
  • Describe the purpose of unit testing in Go. How do you write and organize tests in Go?
  • Explain the concept of interfaces in Go. How do empty interfaces (interface{}) and type assertions work?
  • Discuss the use of reflection in Go. When is it appropriate, and what are the potential drawbacks?
  • Discuss the advantages and challenges of using Go in a microservice architecture.
  • Explain techniques for optimizing the performance of a Go application. How do you identify and address bottlenecks?
  • Discuss the role of distributed tracing and logging in a distributed Go system. How would you implement them?
  • Describe your approach to refactoring legacy code in Go. What factors do you consider?

SQL

  • What is SQL, and what is its primary purpose in the context of databases?
  • Describe the difference between INNER JOIN and LEFT JOIN in SQL. Provide an example of when you might use each.
  • What is normalization in the context of database design? Why is it important?
  • Explain the purpose of the GROUP BY clause in SQL. Provide an example query using it.
  • What is an ERD (Entity-Relationship Diagram), and how is it used in database design?
  • Discuss the differences between a primary key and a foreign key. Why are they important in database design?
  • How do you choose between a relational database (e.g., PostgreSQL) and a NoSQL database (e.g., MongoDB) for a given project?
  • What strategies can be employed to optimize SQL queries for better performance?
  • Explain the importance of indexes in a database. When would you create an index, and what considerations are important?
  • Discuss the pros and cons of using stored procedures in a database.
  • What are ACID properties in the context of database transactions? Why are they important?
  • Explain the difference between a database transaction and a database lock.
  • Explain the concept of SQL injection. How can it be prevented in database applications?
  • What methods can be used for database backups? How would you approach database recovery after a failure or data corruption?
  • Explain the concept of database sharding. When would you consider implementing sharding in a database architecture?
  • What are the challenges associated with database sharding, and how can they be addressed?
  • Discuss the benefits of database replication. How does it improve performance and reliability?
  • Explain the difference between master-slave and master-master replication. When would you choose one over the other?
  • What is a database view, and how is it different from a table?
  • How can database views be used to simplify complex queries or enforce security policies?
  • Explain the concept of an indexed view. When would you use an indexed view, and what are the considerations?
  • What is a database trigger, and how is it used? Provide an example scenario where a trigger might be beneficial.
  • Discuss the potential drawbacks of using triggers in a database.
  • Explain the concept of a database transaction isolation level. What are the commonly used isolation levels, and when would you use each?
  • How do you ensure data consistency and integrity in a system with concurrent transactions?
  • What is a materialized view, and how does it differ from a regular view?
  • Discuss the advantages and disadvantages of using materialized views in a database.
  • How do you enforce business rules and data validation using database constraints?
  • Explain the role of CHECK constraints in ensuring data integrity. Provide an example.

PostgreSQL

  • Explain the role of the pg_hba.conf file in PostgreSQL. How is it used for authentication?
  • Discuss the importance of the EXPLAIN command in PostgreSQL. How can it be used to optimize queries?
  • What types of indexes does PostgreSQL support, and how do they impact query performance?
  • What is the PostgreSQL Query Planner, and how does it optimize queries?
  • Describe the use of Common Table Expressions (CTEs) in PostgreSQL. Provide an example of when you might use a CTE.
  • Explain the window functions in PostgreSQL. How are they different from aggregate functions?
  • Discuss the different replication methods available in PostgreSQL. How does streaming replication work?
  • How can you set up High Availability in PostgreSQL? Explain the concept of a PostgreSQL “failover” and how it’s achieved.
  • Explain the JSONB data type in PostgreSQL. How is it different from the JSON data type, and when would you use each?
  • How can you index and query JSONB data in PostgreSQL efficiently?
  • What are PostgreSQL extensions, and how can they be useful? Provide examples of commonly used extensions.
  • How do you handle database migrations and updates in a team setting?

MariaDB

  • What is MariaDB, and how does it relate to MySQL?
  • Discuss the storage engines supported by MariaDB. How do they differ, and when would you choose one over the other?
  • Explain the InnoDB storage engine in MariaDB. What are its key features, and why is it commonly used?
  • How does replication work in MariaDB? Explain the concepts of master and slave in the context of MariaDB replication.
  • What are the advantages and challenges of using Galera Cluster for synchronous multi-master replication in MariaDB?
  • How can you optimize query performance in MariaDB? Discuss tools and techniques available for query analysis.
  • Explain the role of the EXPLAIN statement in MariaDB. How does it help in query optimization?
  • Discuss security features in MariaDB. How can you secure user authentication and access to databases?
  • Explain how to enable and configure SSL for secure connections in MariaDB.
  • How can you perform backups and restores in MariaDB? Discuss the tools and methods available for these operations.
  • Explain the role of the mysqldump tool in MariaDB. What are its limitations, and how can they be mitigated?
  • Discuss the benefits and considerations of using Galera Cluster in MariaDB for high availability and scalability.
  • Explain some of the unique data types offered by MariaDB. How do they differ from standard SQL data types?

MongoDB

  • Explain the concept of BSON in MongoDB. How does it relate to JSON?
  • Discuss the importance of schema flexibility in MongoDB. How does it handle schema design compared to relational databases?
  • Explain the difference between embedding and referencing documents in MongoDB. When would you use each approach?
  • How do you perform a simple find operation in MongoDB? Provide an example.
  • Explain the aggregation framework in MongoDB. When and why would you use it?
  • Discuss the role of indexes in MongoDB. How can you create and use indexes to optimize queries?
  • Explain the different types of indexes supported by MongoDB.
  • What is sharding in MongoDB, and how does it improve scalability?
  • How does replication work in MongoDB, and what is the purpose of the primary-secondary architecture?
  • How do multi-document transactions work in MongoDB?
  • Explain how MongoDB Atlas handles backup and disaster recovery.

Redis

  • Explain the role of Redis as an in-memory data store. How does it leverage RAM for performance?
  • Discuss the various data structures supported by Redis (e.g., strings, lists, sets, hashes, sorted sets). When would you use each?
  • Explain the use of Redis Sets and Sorted Sets. Provide examples of scenarios where they would be beneficial.
  • How does data persistence work in Redis? What are the differences between RDB snapshots and AOF logs?
  • Discuss the impact of enabling or disabling persistence in Redis on performance and data durability.
  • Explain the concept of replication in Redis. How does Redis handle master-slave replication?
  • What are the key considerations when setting up Redis replication for high availability?
  • Discuss the role of Redis Sentinel in high-availability setups. How does it monitor and manage Redis instances?
  • How can you configure and use Redis Sentinel for automatic failover in case of a master node failure?
  • What is Redis Cluster, and how does it provide horizontal scaling and fault tolerance?
  • Explain the process of setting up and configuring a Redis Cluster. What are the key components?
  • Discuss the publish/subscribe (Pub/Sub) mechanism in Redis. How is it used for real-time messaging?
  • Explain scenarios where Redis Pub/Sub is a suitable choice for communication between components.

RabbitMQ

  • Explain the role of a message broker in the context of RabbitMQ. How does it enhance communication between distributed systems?
  • Discuss the concept of exchanges in RabbitMQ. What are the different types of exchanges, and how do they influence message routing?
  • Explain how queues are bound to exchanges in RabbitMQ. What is the significance of routing keys?
  • How do you publish a message to RabbitMQ, and what information does a message typically contain?
  • Discuss the process of consuming messages from a RabbitMQ queue. How is acknowledgment handled, and why is it important?
  • Explain the Direct, Fanout, Topic, and Headers exchange types in RabbitMQ. When would you use each one?
  • How does the routing key influence message delivery in RabbitMQ? Provide examples of scenarios where specific routing strategies would be beneficial.
  • What is a Dead Letter Exchange in RabbitMQ, and how is it used to handle undeliverable messages?
  • Discuss the concept of Dead Letter Queues and how they can be beneficial in RabbitMQ.
  • Explain the significance of message acknowledgment in RabbitMQ. How does it contribute to message reliability?
  • Discuss the concept of transactions in RabbitMQ and when you might use them.
  • What are RabbitMQ plugins, and how can they extend the functionality of RabbitMQ? Provide examples of commonly used plugins.
  • Explain the considerations for setting up a highly available RabbitMQ cluster.
  • How can you monitor and manage RabbitMQ using the RabbitMQ Management Plugin?

Git

  • Explain the purpose of the staging area in Git. How does it contribute to the commit process?
  • Explain the difference between a Git clone and a Git fork. In what situations would you use each?
  • What is a Git branch, and how does branching contribute to collaborative development?
  • Discuss the difference between a fast-forward merge and a three-way merge in Git. When would you encounter each situation?
  • How does Git handle conflicts during a merge operation, and how can conflicts be resolved?
  • Explain the steps you would take to resolve a merge conflict in a Git repository.
  • What is a remote repository in Git, and how do you add a new remote?
  • Explain the difference between git fetch and git pull. When would you use each command?
  • Describe the Gitflow workflow. What are the key branches involved, and how does it facilitate feature development and release management?
  • Discuss the advantages and disadvantages of using a centralized workflow in Git.
  • Provide examples of commonly used Git log commands.
  • Explain the purpose of Git tags, and how are they different from branches?
  • Explain what Git rebase is and how it differs from a regular merge. When would you use rebase instead of merge?
  • Discuss the potential drawbacks and risks of using rebase, especially in a collaborative environment.
  • What is interactive rebase, and how can it be used to modify commit history?
  • Explain the purpose of “squashing” commits during an interactive rebase. When might you choose to squash commits together?
  • Discuss the different merge strategies in Git, such as recursive, octopus, and resolve. When would you choose one merge strategy over another?
  • Explain the Git cherry-pick command. When and why would you use cherry-pick to apply changes from one branch to another?
  • What is the purpose of the “fixup” and “amend” options in Git?
  • Discuss the Git bisect command. How can it be used to identify the commit that introduced a bug in a codebase?
  • Explain the process of using Git bisect to perform a binary search for a specific commit in a range.

RESTful

  • Explain the key principles of RESTful architecture. How do these principles contribute to the design of RESTful APIs?
  • Discuss the importance of resource URIs in RESTful API design. What are the characteristics of a well-designed URI?
  • Describe the statelessness principle in RESTful architecture. How does it benefit scalability and simplicity?
  • Explain how stateless communication is achieved in REST, and discuss the implications for server and client interactions.
  • Explain the structure of a RESTful request. What are the key components, including headers, methods, and URI parameters?
  • Discuss the structure of a RESTful response. How does it include information about the request’s success or failure?
  • What is content negotiation in REST, and why is it important? How can clients and servers negotiate the format of the exchanged data?
  • Explain how pagination is typically handled in RESTful APIs. What are common strategies for implementing pagination in large datasets?
  • Discuss the purpose of CORS in the context of RESTful APIs. How does it address security concerns related to cross-origin requests?
  • What are the different approaches to API versioning in RESTful services? Discuss the pros and cons of each approach.

gRPC

  • What is gRPC, and how does it differ from traditional HTTP/REST APIs?
  • Explain how Protocol Buffers (protobuf) are used in gRPC for message serialization and communication.
  • Discuss the advantages of using Protocol Buffers over JSON for data serialization in gRPC.
  • How does protobuf contribute to versioning and backward compatibility in gRPC services?
  • Differentiate between unary and streaming RPCs in gRPC. Provide examples of scenarios where each type of RPC is beneficial.
  • Discuss bidirectional streaming RPCs in gRPC. How do they facilitate real-time communication between clients and servers?
  • What are gRPC interceptors, and how can they be used to add cross-cutting concerns to gRPC services? Provide examples of use cases for interceptors.
  • Explain how errors are handled in gRPC. What types of errors can occur, and how are they communicated between the client and server?
  • Discuss the concept of deadlines and timeouts in gRPC. How do they contribute to the reliability and responsiveness of gRPC services?
  • How is authentication handled in gRPC services? Discuss the available authentication mechanisms, such as TLS and token-based authentication.
  • Explain the purpose of gRPC health checking. How can it be used to monitor the status of gRPC services?

Docker

  • Explain the difference between a Docker container and a virtual machine. How does Docker achieve lightweight and efficient containerization?
  • Discuss the lifecycle of a Docker container, from creating an image to running and stopping a container.
  • What is Docker Compose, and how does it simplify the management of multi-container applications?
  • How does Docker handle networking between containers? Explain the concepts of bridge networks and overlay networks.
  • Discuss the differences between named volumes and host-mounted volumes in Docker.
  • What is Docker Swarm, and how does it enable orchestration of Docker containers in a cluster?
  • Discuss best practices for securing Docker containers. How can you minimize security risks and vulnerabilities in a Dockerized environment?
  • Explain the concept of Docker Content Trust (DCT) and how it enhances container image security.
  • How can Docker be integrated into a CI/CD pipeline? Discuss the advantages of using Docker containers in the development and deployment process.

Kubernetes

  • Explain the difference between Docker and Kubernetes. How do they complement each other in a containerized environment?
  • Discuss the key components of the Kubernetes architecture, such as nodes, pods, services, and controllers. How do they work together to manage containerized applications?
  • Explain the role of the Kubernetes Control Plane and Worker Nodes. What components are included in each?
  • What is a Kubernetes pod, and how does it relate to containers?
  • Discuss Kubernetes deployments. How do they enable the management of replica sets and rolling updates?
  • Explain the purpose of Kubernetes services. How do they provide stable networking for pods?
  • Discuss Kubernetes Ingress. How does it facilitate the management of external access to services within a cluster?
  • What are ConfigMaps and Secrets in Kubernetes, and how are they used to manage configuration data and sensitive information?
  • Discuss best practices for managing and securing ConfigMaps and Secrets in Kubernetes.
  • Explain the concepts of Persistent Volumes (PVs) and Persistent Volume Claims (PVCs) in Kubernetes. How do they enable data persistence for applications?
  • Discuss the different types of storage classes in Kubernetes and their use cases.
  • How does networking work in a Kubernetes cluster? Discuss container-to-container communication and pod-to-pod communication.
  • Explain the use of Kubernetes network policies. How can they be used to control the communication between pods?
  • What is Helm, and how does it simplify the deployment and management of applications in Kubernetes?
  • Discuss the use of Helm charts. How do they define, install, and upgrade even the most complex Kubernetes applications?
  • Explain Horizontal Pod Autoscaling in Kubernetes. How does it dynamically adjust the number of replica pods based on observed metrics?
  • What are Kubernetes Operators, and how do they extend the functionality of Kubernetes by automating operational tasks?
  • Discuss examples of scenarios where Kubernetes Operators are particularly useful.

Prometheus

  • Explain the key features of Prometheus that make it suitable for monitoring and alerting in distributed systems.
  • Describe the architecture of Prometheus, including its components such as the Prometheus server, Push Gateway, client libraries, and exporters. How do these components work together?
  • How does Prometheus handle and store time-series data? What is the significance of the multi-dimensional data model in Prometheus?
  • What is PromQL, and how is it used for querying and analyzing metrics data in Prometheus? Provide an example of a PromQL query.
  • Discuss the role of alerting in Prometheus. How are alerting rules defined, and how are alerts triggered?
  • How does Prometheus handle scalability, especially in large and dynamic infrastructures?
  • What is the Prometheus Operator, and how does it simplify the management of Prometheus in Kubernetes environments?
  • Discuss the role of Prometheus in monitoring containerized environments, such as Kubernetes and Docker.
  • Explain how Prometheus supports scraping metrics from various sources, and how it can be configured to monitor different types of services.
  • What are some best practices for optimizing the performance and reliability of Prometheus in a production environment?

Clean Architecture

  • What is Clean Architecture, and what are its core principles?
  • Explain the concept of Dependency Rule in Clean Architecture. How does it contribute to the flexibility and maintainability of the codebase?
  • Describe the layers in Clean Architecture. What are the responsibilities of each layer, and how do they interact?
  • Discuss the significance of the Entity, Use Case (Interactor), and Interface Adapters layers in Clean Architecture. How do they contribute to the design?
  • How does Clean Architecture address the dependency inversion principle? Why is it crucial for creating loosely coupled components?
  • Explain the role of the Frameworks and Drivers layer in Clean Architecture. How does it allow the application to be independent of external tools and frameworks?
  • What is the difference between business rules and application logic in the context of Clean Architecture? How are they separated in the design?
  • How does Clean Architecture support testability? Discuss the ease of writing unit tests for components in each layer.
  • Discuss the concept of “plugins” or “interfaces” in Clean Architecture. How can external components be integrated without affecting the core business logic?
  • Explain the concept of Use Cases in Clean Architecture. How are they defined, and what role do they play in orchestrating the flow of data and interactions?
  • How does Clean Architecture support the development of applications that can easily adapt to changing requirements or technological advancements?
  • Discuss the challenges or trade-offs that developers might face when implementing Clean Architecture in a real-world project.
  • What role does the Presenter (or ViewModel) play in Clean Architecture, especially in the context of user interfaces and interactions?

Domain-Driven-Design

  • Explain the core concept of a “domain” in DDD. How does DDD encourage collaboration between domain experts and developers?
  • What is the importance of a ubiquitous language in the context of DDD? How does it contribute to effective communication between technical and non-technical stakeholders?
  • Define the concept of Bounded Context in DDD. How does it help manage the complexity of large software systems?
  • Discuss the relationship between Bounded Contexts and how they enable different models within the same system.
  • Differentiate between Entities and Value Objects in DDD. Provide examples of each and discuss when to use them.
  • Explain the characteristics of an Entity, including identity and mutability. How does an Entity differ from a simple data structure?
  • Discuss the characteristics of a Value Object. How are they used to represent immutable, interchangeable elements of the domain?
  • Define Aggregates in DDD. What role do they play in ensuring consistency and transactional boundaries within the domain?
  • Explain the concept of an Aggregate Root. Why is it crucial for maintaining the integrity of the aggregate?
  • What are Domain Services in DDD, and when should they be used? Provide examples of scenarios where Domain Services are beneficial.
  • Discuss the relationship between Domain Services and Entities or Value Objects. How do they collaborate to fulfill domain logic?
  • Explain the purpose of Repositories in DDD. How do they provide a way to access and persist aggregates within the domain?
  • Discuss the difference between a Repository and a traditional data access layer. How does a Repository fit into the DDD architecture?
  • What is Event Storming, and how can it be used in the initial phases of a DDD project to discover and model domain events?
  • Discuss the benefits of using Event Storming as a collaborative modeling technique. How does it help build a shared understanding of the domain?
  • Define the Anti-Corruption Layer in the context of DDD. How does it help maintain consistency when integrating different Bounded Contexts?
  • Discuss the challenges and strategies for implementing an Anti-Corruption Layer in a software system.

CQRS

  • What is CQRS (Command Query Responsibility Segregation), and what problem does it address in software architecture?
  • Explain the core principles of CQRS, particularly the separation of commands and queries. How does it contribute to system design?
  • Differentiate between commands and queries in the context of CQRS. How are they handled differently in terms of processing and data retrieval?
  • Discuss the reasons behind segregating commands and queries. How does it impact the scalability and performance of a system?
  • Explain how commands are handled in a CQRS architecture. What happens when a command is received, and how is it processed to update the system state?
  • Discuss the role of command handlers and how they interact with the domain model to execute business logic.
  • How are queries handled in a CQRS architecture? Describe the process of retrieving data for read operations.
  • Discuss the role of query handlers and how they interact with read models or projections to serve query requests.
  • Define Event Sourcing in the context of CQRS. How does it differ from traditional database approaches for storing state?
  • Explain the concept of events and aggregates in the context of Event Sourcing. How are events used to reconstruct the state of an entity?
  • How are events generated and handled in a CQRS and Event Sourcing system? Discuss the relationship between events and their impact on read and write models.
  • Explain the role of event handlers in updating read models or projections. How are events used to keep the read side of the system consistent?
  • Discuss the challenges and strategies for maintaining consistency between the write and read sides in a CQRS architecture.
  • How does eventual consistency play a role in CQRS, especially in distributed systems?
  • Discuss the benefits of adopting CQRS in a software system. In what scenarios does CQRS offer advantages over a traditional monolithic architecture?
  • What are some potential drawbacks or challenges associated with implementing CQRS? How can these challenges be mitigated?
  • Discuss the relationship between CQRS and messaging patterns, such as publish-subscribe or message queues. How do these patterns enhance the scalability and decoupling of a CQRS system?

SOLID

  • What is the Single Responsibility Principle (SRP), and how does it guide the design of software components?
  • Define the Open/Closed Principle (OCP). How does it promote extensibility without modifying existing code?
  • Explain the Liskov Substitution Principle (LSP). How does it ensure that derived classes can be used interchangeably with their base classes without affecting the correctness of the program?
  • Define the Interface Segregation Principle (ISP). How does it advocate for smaller, specific interfaces rather than large, monolithic ones?
  • Explain the Dependency Inversion Principle (DIP). How does it promote decoupling between high-level modules and low-level details?
  • What challenges might developers face when trying to adhere to SOLID principles, and how can these challenges be addressed?

Last Words

So many questions. Too many, in fact. Your purpose shouldn’t be to cover them all in one go.
The best approach, I would think, is to keep revisiting them frequently. Each time, focus on a few. Try to broaden your knowledge on the matter, read about it and some more on similar subjects. If it’s something you’re not familiar with, put time to explore it and learn about its concepts.

Keep in mind, interviewers are trying to gauge your abilities and experiences. All these questions are simply a starting point, discussion opener. If you don’t know the response, don’t be afraid to admit it!
Ask for guidance. Include the interviewer in the conversation. Query for their inputs. Demonstrate how well you can communicate. Maybe you did a project related to something similar? Or you once used a tool reminiscing to this one?

I wish you luck! As always, feel free to let me know what you think. Share some questions you were asked, or any thoughts you have on these questions.

Cheers, Hossein :)