Architecting for Scale, 2nd Edition

Chapter 14. Types of SaaS and Tenancy

Software as a Service, or SaaS, is a term in common use today. At the most basic level, SaaS refers to software that is run and operated by a third party on its computers, rather than being run and operated by you on your own computers.

But SaaS can be a very misleading term. Some companies that have made on-premises (on-prem) software in the past have decided to “go into the cloud” and provide a SaaS offering. Often they do this by taking the same software they sell to customers and installing it on their own hardware in their own data center. They call this a “cloud” offering and call themselves a “SaaS” company.

Although this might be called a SaaS offering, it’s nothing more than basic managed hosting. The company is hosting the software for you, but you still have your own instance of the software, and your company (or a third-party vendor) needs to manage that software instance. Such offerings have all the problems, version issues, and painful upgrades associated with on-prem software solutions. This results in slower new feature development, slower bug fixing, higher costs, and more downtime.

And they have all the same scaling problems of on-prem solutions.

They may call this SaaS, but you aren’t really getting the benefits of SaaS.

Let’s take a closer look at the different types of SaaS services to understand how they can be utilized to help you scale your applications.

Comparing Managed Hosting and Different Types of SaaS

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