Cloud services come in many flavours. One of the most popular is Software as a Service, or SaaS. The provider installs the software and makes it available to customers, who don't otherwise have access to the host machines. This lets the host offer a high level of consistency and security and saves the customer the effort of setting up a complete computing environment.

In a broad sense, you're using SaaS any time you log into an interactive website, such as Facebook, but the term is normally used for services that charge a subscription fee. If they have both free and paid services, only the paid ones count as SaaS.

Popular services include Microsoft Office 365, Salesforce, and the premium features of LinkedIn and Dropbox.

SaaS development works differently from software that''s shipped to customers. There's nothing to deliver or download; a release simply goes out to the website. This allows frequent releases with smaller incremental changes. Developers first roll out a new release to a QA site for shaking out bugs, then perhaps to a beta site for selected users who are willing to take a chance. Once the software passes those tests, it''s rolled out to the public site. The vendor may or may not issue an announcement.

Large operations sometimes install new releases only on some of their public servers to start with. This isn't the same as a beta release, since any users might get the new features. If there's a bug or the changes prove unpopular, this gives a chance to roll back the change without doing too much damage. Only after the new release proves its worth does it become the default installation.

Security is a major concern for SaaS development. Since the software runs on a public server, it needs to be safe against unauthorised access, and users need confidence that no one can improperly view or modify their data.

Scalability is central. A successful service will have a lot of customers, and its software will run on multiple servers. The software needs to allow flexible load sharing among the servers, so that no one of them will slow down its users by carrying an excessive share of the work.

We can provide the assistance you need for your software projects, regardless of their complexity.