How SaaS Systems Really Work

We’ve been putting this off for a while, not because it’s a challenging topic, but because we wanted to cover more practical and pressing issues first. But now, we finally have the time and propriety to actually talk about how SaaS systems actually work.

We understand the basics, right? SaaS is delivered over an internet connection, with most heavy processing and storage handled on the server. This allows weaker devices to do stronger things, and it means no local installations or software discs are necessary.

But, how do SaaS systems work?

Understanding Web:

First, let’s talk a little about how the internet works. Don’t worry, this isn’t going to be complicated. First, let’s be specific and talk about the web, as in anything going through a browser.

Generally, this is a series of web pages, which themselves are made of a series of different files linked together with some script that talks about layout and the like.

So, a browser makes a request to a server, which then sends it a page of marked up data. This data includes text, styles and layouts, as well as links to other contents, such as video, audio and graphics. Then, as it draws the page, it requests those individual files as it sees links for them, and then renders the result.

With a complex page, or a slower connection, you can watch the browser doing this.

Web Seems Linear:

Yeah, if you just send a request, and then it sends you a batch of static data, then really, the only way to steadily do input and output over such a structure would be constant queries and lengthy responses.

Traditionally, early SaaS had to work that way. And that is why early browser software sucked. It required submission and refreshing for every single action or change.

Still, it was possible, as programming could be executed on the server’s side, to calculate variables, follow logic, read and write data and all the other things software does. It just lacked the instant interaction that local software could do.

Enter Broadband and Flash, Java, AJAX and HTML5:

Along came some new technologies that solved that static reload and submit/request nonsense. With these client side systems which made programmable interactive structures, you could suddenly make web pages very interactive, and resemble software, games and other local systems.

On their own, they couldn’t affect the server. However, since they can repeat tasks thousands of times per second like a PC program, they can make constant queries to the server not unlike requesting something through the browser does in the first place.

So now, with these dynamic interface technologies, fast internet, and strong calculation capacity on the side of the server, the web is like a giant PC circuit, and usually, it’s about as fast (at least it seems that way).

So it’s just Fancy Websites:

Yes, that’s all SaaS really is. It’s a website with an aesthetic and usability model based on software, using interactive web technologies and sophisticated database and calculation systems that every other web service uses, to approximate an experience just like local software.

What Feels Different:

Oh, you’ll notice some subtle differences despite them acting just like traditional software in usability concerns. You’ll have a different kind of saving and retrieval of your files or information on there, and you’ll find yourself replacing a desktop and series of windows with a dashboard and a series of frames or tabs. Nothing severe.


And that’s how SaaS systems work. The same way any website does.


Omri is the Head of Demand Generation, as well as the Lead Author & Editor of the SaaSAddict Blog. Omri established the SaaSAddict blog to create a source for news and discussion about some of the issues, challenges, news, and ideas relating to SaaS and cloud migration.