PaaS vs IaaS vs SaaS: Choosing the Right Cloud Model

Cloud models describe how you use computing resources. The three common options are IaaS, PaaS, and SaaS. Each model shifts some work from you to the provider. The choice affects control, speed, and cost. With clear goals, you can pick the right model for your team.

What each model covers

  • IaaS: You get virtual machines, storage, and networks. You decide the operating system, runtimes, and data. The provider handles hardware, power, and cooling. Example: AWS EC2, Azure Virtual Machines.
  • PaaS: The platform runs the runtime and middleware. You deploy code, and the system scales and updates for you. You focus on features, not server maintenance. Example: Heroku, Google App Engine.
  • SaaS: You use software hosted by the provider. No setup or maintenance of the app is needed. Your job is to use the tool and manage data. Example: Gmail, Salesforce.

When to choose

  • You need full control over the stack, custom configurations, and strict compliance. IaaS fits.
  • You want to ship apps quickly with built-in scaling and less operations work. PaaS fits.
  • You want ready software with minimal setup and ongoing maintenance. SaaS fits.
  • Many teams mix models: SaaS for common tools, PaaS or IaaS for custom apps and data-heavy work.

Getting started

  • Assess your team skills, project goals, and budget.
  • List required controls, such as OS updates or data residency.
  • Compare providers on SLAs, security features, and total cost of ownership.
  • Run a small pilot to learn how the model affects your workflow and costs.

Example scenarios

  • A web store with custom checkout needs: a mix of IaaS for the backend and SaaS for marketing tools.
  • A development team building a new app: start with PaaS to move fast, then add IaaS if you need more control.
  • A company using email and CRM: SaaS programs save time and reduce maintenance.

By understanding what you gain or give up with each model, you can plan a cloud path that fits people, processes, and price.

Key Takeaways

  • Match your need for control and speed to IaaS, PaaS, or SaaS.
  • Start with small pilots and compare costs, SLAs, and data portability.
  • A hybrid approach is common, using SaaS for core tools and PaaS/IaaS for custom apps.