Domain purchase. Software deployed. Customer acquisition strategy? Go to market strategy? Free at outset or charge nominally for beta users? Business partner strategy? Roadmap available? Metrics and KPI targets?
My best advice would be to get to MVP as early as possible.
When I say MVP I mean functional, not beautiful. It just needs to show basic functionality and can be worked on and enhanced from there.
Your SaaS product needs to get in the hands of users as soon as possible as they will show the direction it should take or that it's not worthy of their time (and/or money).
