Hey Growthbook team, Wanted to check the best approach for splitting users 50/50 across saved groups (SGs). Example: • SG-1 → 100 users → (50 control / 50 variation) • SG-2 → 50 users → (25 / 25) • SG-3 → 5000 users → (2500 / 2500) The goal is to ensure the control/variation split happens proportionally within each SG. One easy way is creating separate experiments for each SG, but with ~100 SGs that becomes messy to set up and track. Is there a more scalable way (like using a single experiment with attribute-based targeting or hashing on

user_id

within each SG) so the split auto-balances across all SGs, instead of 100 separate experiments? Thank you!

So, there is no built-in way in GrowthBook to guarantee a 50/50 split within each saved group using a single experiment. You would need to either run separate experiments per group (like you said) or implement custom assignment logic outside of GrowthBook and use it for analysis.

Noted, Thanks!

just wanted to chime in that I am in the same situation, which prompted my question regarding API interactions as I'd like to be able to programmatically create and manage all of the experiments needed.

@strong-mouse-55694 is it possible if I create different namespaces for each Saved Group as they are going to be mutually exclusive. Will growthbook ensure split happens uniformly across namespaces under a same experiment? Or how can i implement this > Implement custom assignment logic outside of GrowthBook and use it for analysis. like what will be assignment > variation attribute be

• It's not possible to namespace Saved Groups. They are independent in that sense that they aren't aware of each other. • The outside assignment logic: You would pre-assign users to control/variation within each group and store that assignment as a user attribute and then use that attribute for assignment in GrowthBook.