29 Cloud Service Models: SaaS, PaaS, and IaaS
These are three main categories of cloud computing services, representing different levels of abstraction and management responsibility.
29.1 The Stack Visualization
┌─────────────────────────────────────────────────────────────┐
│ SaaS │
│ ┌──────────────────────────────────────────────────────┐ │
│ │ Application (Gmail, Slack) │ │
│ └──────────────────────────────────────────────────────┘ │
│ Data | Runtime | Middleware | OS | etc. │
│ ALL MANAGED FOR YOU │
└─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐
│ PaaS │
│ ┌──────────────────────────────────────────────────────┐ │
│ │ Your Application & Data (YOU MANAGE) │ │
│ ├──────────────────────────────────────────────────────┤ │
│ │ Runtime | Middleware | OS | Virtualization | etc. │ │
│ │ (PROVIDER MANAGES) │ │
│ └──────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐
│ IaaS │
│ ┌──────────────────────────────────────────────────────┐ │
│ │ Application | Data | Runtime | Middleware | OS │ │
│ │ (YOU MANAGE) │ │
│ ├──────────────────────────────────────────────────────┤ │
│ │ Virtualization | Servers | Storage | Networking │ │
│ │ (PROVIDER MANAGES) │ │
│ └──────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────┘29.2 1. IaaS (Infrastructure as a Service)
What you get: Virtual machines, storage, networks - the raw computing infrastructure
What you manage: Everything from the OS up (operating system, runtime, middleware, data, applications)
Examples: - AWS EC2 - Virtual servers in the cloud - Google Compute Engine - VM instances - DigitalOcean Droplets - Simple virtual machines - Azure Virtual Machines
Use case: You want full control over your infrastructure but don’t want to manage physical hardware.
29.3 2. PaaS (Platform as a Service)
What you get: A platform to deploy your application without managing infrastructure
What you manage: Just your application code and data
Examples: - Netlify (you’re already using this!) - Deploy static sites - Firebase Hosting (you have this!) - Host web apps with backend services - Heroku - Deploy apps from Git - Google App Engine - Scalable web applications - Vercel - Deploy Next.js and other frontend apps
Use case: You want to focus on coding your app, not managing servers, databases, or scaling.
29.4 3. SaaS (Software as a Service)
What you get: Ready-to-use software applications
What you manage: Just your data and configuration
Examples: - Gmail - Email service - Google Workspace - Office suite - Slack - Team communication - Dropbox - File storage - Salesforce - CRM software - Claude.ai - AI assistant (yes, this!)
Use case: You just want to use the software without installing or maintaining anything.
29.5 Relevant to Your Work
Your Current Stack:
┌────────────────────────────────────────┐
│ Code Editor (VSCode, RStudio) - Local │
│ ↓ │
│ Git/GitHub - Version Control (SaaS) │
│ ↓ │
│ Quarto - Build docs (Local) │
│ ↓ │
│ Netlify/Firebase - Deploy (PaaS) │
│ ↓ │
│ End Users Access Your Site │
└────────────────────────────────────────┘For medical imaging AI projects: - IaaS: Use EC2/GCE if you need GPU instances for training deep learning models - PaaS: Use Firebase for hosting your AI model inference API - SaaS: Use Claude API or other AI services in your applications
The key difference is the responsibility boundary - as you move from IaaS → PaaS → SaaS, you manage less and the provider manages more.