I've lived through this situation-I lived, but the product died. My boss at the time was the primary developer (really, only developer) of our healthcare web ap

I've lived through this situation-I lived, but the product died. My boss at the time was the primary developer (really, only developer) of our healthcare web app. He had been hacking on it in one for or another for over a decade. Guy up and has a stroke one morning getting out of bed and dies. Database documentation has no bearing on reality, all of his reporting code was uncommented. All of his programs were 8 character max camelCase names with no (to me) bearing on their function. Product basically died with him-I've kept it running in a zombie fashion, but all new features or even creating new reports is impossible.