I am looking for a word to describe a system or solution that has been put together from pre-existing parts. For example if a computer company gets software from 3 different software houses and sells it together as a complete solution maybe with some integration work on their part. The company might even white-label the system/solution and the customer may not even be aware that the system has been put together from constituent parts. The word could be IT industry specific but it doesn't have to be.
I always thought the word 'turnkey' meant this but I have found that 'turnkey' really means the opposite (ie an off-the-shelf system) and bespoke is a closer word but a bespoke system implies to me that it has been created entirely from scratch to the customer's specifications whereas the word I am looking for is more like 'assembled' really but that seems a bit weak.