I'm more familiar with the design side of things and not as strong on the development side, so I'm curious for any input that you may have.

I have a client who is trying to build a startup that helps businesses acquire customers in a unique way. His solution is a standalone tool that can be linked to from other websites. The tool will require an admin site that customers can use to manage it, plus a branded site that will be mainly for logging in / marketing purposes. This tool is versatile enough that he thinks he can attack multiple industries with it. So he is trying to figure out the best way to approach it, with that end goal in mind. He is thinking he wants to use a Bootstrap theme for the admin side and custom built pages for the external marketing side. His reasoning is that the admin stuff needs to be built quickly, it can be easily altered by back end guys without breaking too much front end stuff in the process, and it isn't as important what it looks like. Keep in mind, whatever is done on the site for the first industry will basically be copied and used again for the others.

I haven't really seen this approach before, but it sounds plausible. I'm mainly wondering if this could create any issues with maintenance since you effectively have two completely separate sets of front end code - and then you're multiplying that by the number of industries that this guy chooses to enter. Thoughts?