Intermediate · 16 lessons
Cloud Computing
Cloud computing delivers computing resources over the internet on demand. Instead of buying physical servers, you rent virtual machines, storage, and services from providers like AWS, Google Cloud, and Azure — paying only for what you use with the ability to scale instantly.
Key Concepts
Key Takeaways
- ✓ Cloud eliminates upfront hardware costs — scale up or down on demand.
- ✓ IaaS gives VMs; PaaS manages runtime; SaaS is ready-to-use software.
- ✓ Deploy across multiple availability zones for high availability.
- ✓ Monitor cloud bills — unused resources and data transfer add up fast.
Lessons in This Topic
Cloud Computing Fundamentals
IaaS, PaaS, SaaS — what each model means.
IaaS (AWS EC2, DigitalOcean Droplets) — you manage OS and apps. PaaS (Heroku, Vercel) — provider manages runtime, you deploy code. SaaS (Gmail, Salesforce) — fully managed software. Most web apps use IaaS or PaaS depending on control vs convenience tradeoff.
Virtual Machines & Instances
Launch, configure, and connect to cloud VMs.
Create an instance: choose region, OS image, instance size (vCPU + RAM), storage, and security group (firewall rules). Connect via SSH using key pairs. Attach elastic IPs for static addresses. Use snapshots for backups and golden images for repeatable deployments.
Auto-scaling & Load Balancing
Handle traffic spikes automatically.
Load balancers distribute traffic across multiple servers. Auto-scaling groups add/remove instances based on CPU, memory, or request count. Health checks remove unhealthy nodes. Combine with CDN for static assets. Test scaling policies before Black Friday traffic.
Cloud Storage: S3 & Object Storage
Store files, backups, and static assets.
Object storage (AWS S3, Google Cloud Storage) stores files as objects with unique keys. Use for backups, media uploads, static site hosting, and log archives. Set lifecycle rules to move old data to cheaper tiers. Enable versioning and cross-region replication for disaster recovery.
Cloud Security Best Practices
IAM, security groups, and encryption.
Use IAM roles with least privilege — never hardcode API keys. Security groups act as firewalls per instance. Enable encryption at rest (AES-256) and in transit (TLS). Use VPCs to isolate networks. Enable CloudTrail/logging for audit. Rotate credentials regularly.