i did this a loooong time ago with coldfusion and the saas i wrote. in the beginning each customer had their own database and instance of the application. at th

i did this a loooong time ago with coldfusion and the saas i wrote. in the beginning each customer had their own database and instance of the application. at the time i had 25+ customers and doing update to the application or the database took the entire weekend. over the course of 2 months i wrote everything into a multi tenet app with a single database and never looked back. i think that my thinking at the time that it would be easier from a security perspective since everyone had their own data and also speed wise since multiple smaller database could fit into memory better. security wise, especially with an orm, it's not a huge concern as long as you use the top level model as an entry point, it will isolate everyone 95% of the time. as for database sizes... we live in a world now where you can pretty much scale in an instance by throwing more virtual resources at anything, so i wouldn't worry.