Dynamic Yield is used by three teams within the web trading function in Ocado General Merchandise. It is used mainly as a personalization software but also to implement changes to the websites which might have taken longer before.
The support team is one of the best I have worked with. With any new software and business implementation, there are inevitably unforeseen teething issues. Dynamic Yield is always quick to react and even with problems that I couldn't see easy ways of fixing, there always are.
The portal is very user-friendly.
The code is very easy to amend and change to your business needs.