http://ayende.comAyende @ RahienCopyright (C) Ayende Rahien 2004 - 2021 (c) 202660You've listed alot of good ideas here... most consistent with a system I am designing. One thing to keep in mind with points of extension is the add-in framework released with .Net. It really helps with the versioning issue of add-ins. BOb http://ayende.com/3507/multi-tenancy-development-structure#comment2http://ayende.com/3507/multi-tenancy-development-structure#comment2Mon, 11 Aug 2008 15:24:10 GMTI work on a mult-tenant product with at the minute only 4 different tenants. I have migrated the app. from ASP and the ASP approach was to have a completelly seperate code stream for every customer and a seperate DB strucutre. This was quickly getting out of hand. I migrated all code streams into one app and every tenant now has their own DB instance of the same schema. I am loathe to go down the path of actually developing maintainable bits of work that are only applicable for one tenant. The variability has to be controlled by configuration, DSLs or maybe even clever use of build scripts that all build from the same code base. The important part of the latter approach is being able to easily rebuild the tenants specific configuration for debugging purposes. The minute you start developing single pieces of work for one customer then I think you are heading down a very dark tunnel. Our approach at the minute is that if it is not good for the core product and only applicable to one tenant then we just say no. http://ayende.com/3507/multi-tenancy-development-structure#comment1http://ayende.com/3507/multi-tenancy-development-structure#comment1Sat, 09 Aug 2008 17:51:59 GMT