I am currently working on a personal banking platform that, due to various internal reasons, will rely heavily on a 3rd party platform/software. My company would like to move away from the use of the 3rd party platform over the coming 1-2 years and have complete control of the platfom itself.
Doing so could result in the website having a different design, and updated functionality (not changing the core proposition of the service however).
I am particularly looking for any information regarding stragies for migrating new vs existing users, how to approach such a switchover and any other information that anyone might have.
I know of more high-profile migrations, such as Facebook and the BBC, but would be hugely greatful for any other insight. At present I am doing some very early research and so any help is greatly appreciated!