Summary of "AWS Interview Questions And Answers 2025 | Top 30 AWS Interview Questions | Intellipaat"

This video by Intellipaat provides a comprehensive guide to the top 30 AWS interview questions categorized into three difficulty levels: easy, medium, and hard. The content covers fundamental AWS concepts, services, architecture, security, cost optimization, and disaster recovery, with detailed explanations and analogies to simplify understanding.

Main Ideas, Concepts, and Lessons:

Introduction & Context

Cloud adoption is rapidly growing globally, especially in India, China, and Japan.
AWS launched in 2006 and currently leads the cloud market with the most compute and storage options.
AWS-related job opportunities are abundant, with competitive salaries that grow significantly with experience.
The video covers 30 frequently asked AWS interview questions divided into easy, medium, and hard modules.

Easy Module (Basic Concepts & Services)

What is AWS?
- AWS is a cloud computing platform offering on-demand infrastructure without on-premise hardware.
- Pay-as-you-go pricing.
- Popular services: EC2, Lambda (compute), S3, EBS (storage), RDS, DynamoDB (databases), Route 53 (DNS), IAM (security), SageMaker (ML).
Key Components of AWS+Amazon+S3+storage+course&tag=dtdgstoreid-21">Amazon S3
- Stores data in buckets (globally unique names).
- Objects inside buckets contain data + metadata.
- Keys uniquely identify objects (like file paths).
- Supports versioning and encryption (server/client-side).
Types of Cloud Computing Models
- IaaS (Infrastructure as a Service): Rent raw infrastructure (e.g., EC2).
- PaaS (Platform as a Service): Rent a platform to deploy apps (e.g., Elastic Beanstalk).
- SaaS (Software as a Service): Use fully managed software (e.g., Office 365, Zoom).
AWS+Amazon+EC2+beginner+guide&tag=dtdgstoreid-21">Amazon EC2 Overview
- Virtual servers rented on-demand.
- Choose size, power, and pay only for usage.
Stopping vs Terminating EC2 Instances
- Stop: Temporarily shut down, instance persists, IP may change.
- Terminate: Delete instance and storage permanently.
Availability Zones and Regions
- Region: Geographically isolated area (like a city).
- Availability Zone: Isolated data centers within a region (like neighborhoods).
- AWS has 34 regions and 108 availability zones globally.
AWS+Elastic+Load+Balancer+tutorial+book&tag=dtdgstoreid-21">Elastic Load Balancer (ELB)
- Distributes incoming traffic across multiple servers.
- Ensures high availability and fault tolerance.
- Health checks route traffic only to healthy servers.
Horizontal vs Vertical Scaling
- Horizontal: Add/remove instances (scale out/in).
- Vertical: Increase/decrease instance capacity (scale up/down).
AWS+IAM+security+course&tag=dtdgstoreid-21">AWS IAM (Identity and Access Management)
- Controls who (users, roles) can access what (AWS resources).
- Provides granular permissions and temporary access.
Security Groups vs Network ACLs
- Security Groups: Stateful, instance-level firewall (like room-level security).
- Network ACLs: Stateless, subnet-level firewall (like building-level security).
- Security groups track allowed traffic; ACLs check rules on every request.

Medium Module (Intermediate Concepts)

Amazon Route 53
- DNS service translating domain names to IP addresses.
- Supports latency-based routing directing users to the nearest/least busy server.
- Ensures high availability and low latency.
AWS+Lambda+online+course&tag=dtdgstoreid-21">AWS Lambda
- Serverless compute service running code in response to triggers.
- Pay only for execution time.
- No server provisioning or management needed.
AWS CloudFormation
- Infrastructure as Code service.
- Create templates (JSON/YAML) to define and replicate AWS resources/configurations.
- Ensures consistent infrastructure deployment.
Difference Between Amazon SQS and SNS
- SQS: Message queuing service (one-to-one communication, FIFO).
- SNS: Pub/Sub notification service (one-to-many broadcasting).
- Often used together for reliable message delivery.
AWS+Amazon+RDS+database+course&tag=dtdgstoreid-21">Amazon RDS
- Managed relational database service.
- Automates patching, backups, scaling, monitoring, and high availability.
- Supports multiple database engines (MySQL, PostgreSQL, Oracle, SQL Server).
AWS Well-Architected Framework
- Best practices for building secure, reliable, efficient, and cost-effective systems.
- Five pillars: Operational Excellence, Security, Reliability, Performance Efficiency, Cost Optimization.
Elastic IP
- Static public IPv4 address that remains constant even if the instance is restarted.
- Prevents downtime caused by IP changes.
AWS Elastic Beanstalk
- PaaS for easy deployment and management of applications.