My advice is pretty simple.<p>Start with the customer. If you can get them excited & keep them that way, you solved most of the problem. If you are building something with hopes that "they will come" you are burning cash for fun and no one is going to care when it runs out.<p>The other piece of advice I would add is that, even though SaaS starts with "Software", you should <i>NEVER</i> start with the software. You should be starting with on-site meetings with your customers. Consulting about the processes the software <i>might</i> be able to help with. You should only start talking about things like clouds, containers and code once you have a schema that the <i>customer</i> can look at and go "aha! That's our business!".<p>Both pieces of my advice deeply involve the customer in some way. It's incredible to me how many "entrepreneurs" are blind to the fact that someone is eventually going to have to <i>want</i> their product, and for profitability to occur that prospect probably can't be their family member, SO or best friend.