==Background
The Page Previews feature will be deployed in staged rollouts, beginning with Stage 0: Italian, Russian, Greek, Catalan, Hebrew. The performance on each wikipedia will be measured and analyzed.
== AC
[] T157700 is resolved providing 90% roll out
[] Restbase is enabled on stage 0 wikis (T158221)
[] Determine and apply appropriate sampling rate (if default rate is too high for eventlogging, lower the rate and communicate out to the team)
After the beta feature is graduated make sure:
[] Those logged in users who enabled the beta feature will still have the feature enabled.
[] 90% of logged out users will have the feature delivered to them.
[] Events are logged for all users (as a basis of comparison)
[] Popups schema is updated to include whether the feature is enabled (isEnabled)
[] Feature is not present under the beta feature list
[] Olga, Anthony and TSG run through test plan
== Open Questions
* ~~Should this be implemented by making the Page Previews codebase lazily-loadable?~~ No. Given that all of the interaction handling code and the instrumentation will be required, we (the Reading Web software engineers) consider delaying the initial preview too much of a penalty.
* ~~Should we test all Wikipedias or only a portion?~~ We'll test on all stage 0 Wikipedias.
---
The original wording of this task, which is as follows, is still relevant but approached the problem from a performance perspective:
> There are a handful of instances where the majority of the Popups code needn't be loaded but is:
>
> * When the user has enabled the beta feature but has since disabled it via the settings menu
> * When the user is entered into the A/B test but isn't assigned the enabled condition (see T132604)
> * When the user has the [NavPopups](https://en.wikipedia.org/wiki/Wikipedia:Tools/Navigation_popups) gadget enabled
>
>== AC
>
> Answers on the back of a postcard, sent to mobile-l/wikitech-l:
>
> [ ] Can we really defer the loading of the majority of the codebase?
> [ ] Would it be worth it, i.e. what the impact on UX, if any, be acceptable?
> [ ] If it wouldn't be worth it, are there any small improvements that we can make to improve the status quo?