Due to greater technical complexity, SaaS application development often requires considerable up-front design and architecture work.
Once the key design/development decisions are made, the process often utilizes an Agile development methodology, aimed at bringing modules of the application online as soon as possible.
During ongoing operations, Agile is also a good choice of methodology because designers/developers have real-time access to the SaaS platform and can quickly re-prioritize development in response to user behaviour. SaaS developers can therefore take advantage of 'click-driven' R&D, poll-based development and feature-by-feature release and evolution.
The intimacy of the SaaS platform enables designers/developers to be much more in touch with customer requirements as compared to traditional on-premises software developers, so that not only is the development process more agile, but the whole SaaS business is more agile.