I worked for a personalization vendor a few years ago and was on an engineering team that built a feature like this. It was ... a major headache, and I don't think anyone was ever completely comfortable with the security implications.
So I wish the team good luck, and especially with issues like:
* A/B testing. How can you ensure that what your clients are seeing is the same thing you are seeing? Maybe you've been assigned to different A/B groups.
* Extensions. What if your clients are using Chrome extensions that affect how the page is rendered? How can you replicate that?
* Networking/auth issues. What do you render if you're unable to connect or log in?
So I wish the team good luck, and especially with issues like:
* A/B testing. How can you ensure that what your clients are seeing is the same thing you are seeing? Maybe you've been assigned to different A/B groups.
* Extensions. What if your clients are using Chrome extensions that affect how the page is rendered? How can you replicate that?
* Networking/auth issues. What do you render if you're unable to connect or log in?