Hello everyone! First of all, I want to thank you guys for creating such an amazing platform and keeping it open source, you are doing a great job! 🙌 I want to check with you whether you can validate our current setup, and maybe you can help me find a solution (or other things to try out) to the issues we see around the experiments data: We are using Growthbook in a Next.js application. The setup is the following: • all requests are intercepted in the

middleware

and, if not already set, they set a

unique_id

cookie, that we later use as the

id

attribute when initializing the Growthbook SDK • when the application is mounted client-side, we initialize the Growthbook SDK with the

id

specified above • in our

trackingCallback

, we push an

experiment_joined

event with the

experiment_id

and

variant_id

to our GTM data layer, which, in turn, sends a GA event We set up an A/B Experiment inside our signup flow, that evaluates the value of our experiment (via

growthbook.getFeatureValue

) right before we want to display the tested UI component (there are some extra pre-conditions to the test that are evaluated first). The experiment is running for 100% of traffic, split in equal 33.3% for the Control and 2 Variants we are testing. Everything seems to be normal, but after we deployed this to production, it seems like a lot of the sessions were not part of the experiment. I checked both our

sign_up

and

experiment_joined

events via Big Query and it seems like more than 50% of `sign_up`s did not have a corresponding

experiment_joined

event, even though all conditions seem to have been met. Some extra details in case they help: • I am fairly confident the

id

is already set when the experiment is evaluated, so the user should not be excluded from the experiment - we have Sentry events that should let us know otherwise • We have no other targeting rules set up for the feature flag or the experiment • I am confident in the queries we are running for

sign_up

events and they include the same pre-conditions of the A/B experiment • We are using Big Query as a data source in Growthbook • We are querying both daily and intraday tables of the events in BigQuery with this filter:

FROM
    analytics_<redacted>.`events_*`
WHERE
    (
      (_TABLE_SUFFIX BETWEEN '<START_DATE>' AND '<END_DATE>')
      OR (
        DATE(CURRENT_DATE()) BETWEEN DATE('<START_DATE>') AND DATE('<END_DATE>')
        AND REGEXP_CONTAINS(_TABLE_SUFFIX, '^intraday')
      )
    )

• We are using the Enterprise version of Growthbook • We are running version

^0.17.0

of

@growthbook/growthbook-react

Do you have any suggestions for things I should try out next, to get this issue solved? Thanks!

I checked both our

sign_up

and

experiment_joined

events via Big Query and it seems like more than 50% of `sign_up`s did not have a corresponding

experiment_joined

event

As in when you join or group by these events on

id

there are 50% of

id

with at least one

sign_up

event who do not have a corresponding

experiment_joined

event? Just ruling out that there's some issue with

sign_up

events firing too often.

• I am confident in the queries we are running for

sign_up

events and they include the same pre-conditions of the A/B experiment

To confirm, they are querying the same table?

• in our

trackingCallback

, we push an

experiment_joined

event with the

experiment_id

and

variant_id

to our GTM data layer, which, in turn, sends a GA event

Are there any differences (besides the fact that the tracking callback is getting called within the GB SDK) between this and how you track sign up events? Is it the case that you expect every single

id

that fires a

sign_up

event to also fire an

experiment_joined

event?

Hi @helpful-application-7107, thank you for your reply! Shortly after posting this message, I went and checked again all of our pre-conditions, where I found a bug that made all our non-UK sessions not be bucketed into experiments 🤦‍♂️ The good news is that we are now seeing about the same amount of `sign_up`s as

experiment_joined

events. For the 0.5% that is missing, we are assuming it's people with cookies disabled, or in-app browsers that do not handle our cookie. To quickly answer your questions, yes, we have all events in the same table(s) in BigQuery, the events were fired in the same way, and we were expecting everyone that had a

sign_up

event through a specific flow, to have a corresponding

experiment_joined

event. I appreciate you for jumping on my questions and offering help, thanks again! 🙌