Does growth book require a separate instance of the SDK for each user? IE: If I have a node.js server, and I have 10 users, I have 10 instances of the growthbook SDK initialized in my app, each bound to a particular user via attributes?

Yes, I believe so. Each instance is very light weight so shouldn’t cause any resource problems

To elaborate on this a bit, SDK instance per connection is done by design. There is a central in-memory "feature repository" (basically a singleton created by the SDK) which all SDK instances plug into and subscribe to, so memory usage stays light

Gotcha! Thanks for the details! We were wondering if we’d have to build our own middleware or something to handle that functionality at that point! Thank you!