I've been in charge of a full rewrite of a B2B system that looks to work out pretty well so far (will soon do the full rollout for the first customer after succ

I've been in charge of a full rewrite of a B2B system that looks to work out pretty well so far (will soon do the full rollout for the first customer after successfully piloting with 20 users). I think a key to the success is that the old system is so crufty that it's not, in fact, a moving target. The old system is over 20 years old, a web application written in C. Apart from security considerations, the UI looks archaic, there is no separation between frontend and backend, and data storage is in custom-designed files - no database engine, so it's essentially impossible to add substantial new functionality.Even the most minor config change requires a recompile.