Interview Questions and Answers

Cloud computing is a technology that allows users to access and use computing resources (such as servers, storage, databases, networking, software) over the internet instead of owning and maintaining them locally.

The three main service models of cloud computing are Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS).

Elasticity in cloud computing refers to the ability to dynamically allocate and deallocate resources based on demand. It allows for automatic scaling of resources to handle varying workloads.

A load balancer distributes incoming network traffic across multiple servers to ensure even resource utilization and high availability. It enhances the performance and reliability of applications.

Auto Scaling is a feature that automatically adjusts the number of compute resources in a cloud environment based on demand. It ensures optimal performance without manual intervention.

A VPC provides a logically isolated section of the cloud where you can launch resources. It allows you to define your own network environment with IP address ranges, subnets, and route tables.

IAM controls access to cloud resources by managing user identities, permissions, and authentication. It ensures that only authorized users have access to specific resources.

A CDN is a system of distributed servers that deliver web content to users based on their geographic location. It improves website performance, reduces latency, and enhances user experience.

A server farm is a group of interconnected servers used to provide computing resources. It is designed to ensure high availability, reliability, and scalability for applications and services.

A Key Vault is a secure storage area for cryptographic keys and secrets. It provides centralized management of sensitive information and helps in secure key access and storage.

DevOps is a set of practices that combines software development (Dev) and IT operations (Ops) to shorten the software development life cycle. Cloud computing provides an ideal platform for implementing DevOps practices.

Serverless computing is a cloud computing execution model where the cloud provider dynamically manages the infrastructure. It is advantageous for applications with variable workloads as users are only charged for actual usage.

A Network Security Group is a set of rules that control the inbound and outbound traffic to network interfaces (VMs, load balancers) in Azure. It acts as a basic firewall for controlling traffic flow.

A public cloud is owned and operated by a third-party cloud service provider. A private cloud is used exclusively by one organization. A hybrid cloud combines elements of both public and private clouds.

Virtualization is the process of creating a virtual (rather than physical) version of something, such as a server, storage device, or network resources. In cloud computing, virtualization enables the efficient use of physical resources by creating virtual instances of them.

A hypervisor, also known as a Virtual Machine Monitor (VMM), is a software or hardware component that allows multiple operating systems to share a single hardware host. It manages and allocates resources to virtual machines.

Load balancing distributes incoming network traffic across multiple servers to ensure that no single server is overwhelmed with too much traffic. It improves the performance, availability, and reliability of applications.

Horizontal scaling involves adding more machines or nodes to a system to handle increased load. Vertical scaling involves increasing the resources (CPU, RAM) of an existing machine to handle increased load.

Serverless computing is a cloud computing execution model where the cloud provider manages the infrastructure, automatically allocating resources as needed to execute and scale applications. Developers only focus on writing code without worrying about server management.

Scalability refers to the ability of a system to handle a growing amount of workload. Elasticity, on the other hand, is the ability to automatically adapt to changing workloads by provisioning and de-provisioning resources dynamically.

A CDN is a network of distributed servers that work together to deliver web content, such as images and videos, to users based on their geographical location. It improves performance by reducing latency and increasing content availability.

Container orchestration tools manage the deployment, scaling, and operation of application containers. Kubernetes is a popular container orchestration tool.

Multi-tenancy is a cloud architecture where a single instance of a software application serves multiple customers (tenants). Each tenant's data is isolated and remains invisible to other tenants.

Serverless architecture offers benefits such as reduced operational complexity, cost savings by paying only for actual usage, and automatic scalability. Developers can focus on code without managing servers.

Stateful applications retain information about the state of a user's interactions, while stateless applications do not store such information between sessions. Stateless applications are often more scalable.

A cloud SLA is a contract between a cloud service provider and a customer that outlines the level of service and performance the customer can expect. It is important as it sets expectations and provides a basis for accountability.

BYOD (Bring Your Own Device) is a policy that allows employees to use their personal devices to access company networks and data. In the context of cloud computing, it poses security challenges that need to be addressed.

Cloud Bursting is the process of moving workloads from a private cloud to a public cloud during periods of high demand. It allows organizations to scale up temporarily when local resources are insufficient.

Key considerations include regular backups, data encryption, geographic redundancy, and a well-defined recovery strategy. Ensuring data integrity and availability is crucial for business continuity.

Horizontal scaling involves adding more database nodes to a system, while vertical scaling involves increasing the resources (CPU, RAM) of an existing database server. Horizontal scaling is often more scalable.

Fault tolerance is the ability of a system to continue operating without interruption in the presence of hardware or software failures. Cloud environments use redundancy and failover mechanisms to achieve fault tolerance.

Immutable infrastructure is an approach where once an infrastructure component is deployed, it is never modified. Instead, new instances are created with updates, reducing configuration drift and improving consistency.

Blue-Green Deployment is a strategy where two identical production environments, labeled 'blue' and 'green,' are maintained. Only one environment is active at a time, allowing for seamless updates and rollbacks.

A reverse proxy is a server that sits between client devices and a web server, forwarding client requests to the server and returning the server's responses to the clients. It can improve security, performance, and scalability.

A serverless database is a database service that automatically scales, provisions, and manages infrastructure based on the actual usage. Users are charged based on their consumption, and they don't need to manage database servers.

Infrastructure as Code is a practice of managing and provisioning computing infrastructure through machine-readable script files rather than physical hardware configuration or interactive configuration tools.

Data sovereignty refers to the concept that data is subject to the laws of the country in which it is located. It is an important consideration for organizations dealing with sensitive or regulated data.

Edge computing is a paradigm where data processing is performed near the source of data generation rather than relying on a centralized cloud server. It reduces latency and bandwidth usage for time-sensitive applications.

Key considerations include data security, compatibility, bandwidth, downtime, and ensuring data consistency during migration. A well-planned migration strategy is crucial for a successful transition.

Compliance as Code is an approach that uses code and automation to ensure that IT infrastructure adheres to regulatory and security compliance standards. It helps in maintaining a consistent and auditable compliance posture.

Key security concerns in cloud computing include data breaches, data loss, unauthorized access, insecure interfaces and APIs, and compliance challenges. Security measures like encryption and access controls are crucial.

The CAP theorem states that in a distributed system, it's impossible to simultaneously provide all three of the following guarantees: Consistency, Availability, and Partition tolerance. You can achieve at most two of the three.