Wikimedia Performance Team/Performance Review

The Wikimedia Performance Team provides a service critical to the sanity of Wikimedia production code and infrastructure in the form of Performance Reviews. The goal of these reviews is to ensure that major changes and deployments of new features do not result in performance regressions detrimental to the user experience.

Performance regressions can lead to user frustration and search engine ranking degradation, both likely to result in audience and traffic attrition. Performance reviews are a necessary step for all major changes deployed to Wikimedia production.

Timeline
Performance reviews for a given quarter must be requested at least 30 calendar days prior to the beginning of the financial quarter.

We are a small team and performance reviews are time-consuming, they are quarterly goals for us.

Once preparation steps have been performed by the requester (see below), we commit to completing the performance review within 30 calendar days.

Required preparation
The main prerequisite to a performance review is to have the changes or features deployed to a Beta Cluster wiki.

If that isn't possible, the exception must be justified and the changes/feature will still have to be hosted on a wiki the performance team can access and SSH into. It's insufficient to merely point us to code and ask us to review it. Reviewing must be a zero setup experience for us. This differs from a code review where pushing the code to gerrit is enough preparation for the reviewer.

Beyond setup, it's also necessary for the requester to do a performance assessment of their own. Outlining potential performance bottlenecks, potential optimisations and including performance measurements. Web performance shouldn't be a concern completely offloaded to the Performance Team. New features and major changes should already have had their performance optimised to the best of the authors' abilities prior to being submitted to performance review.

How to request a performance review
Use this Phabricator custom form and fill all the required information. Thank you!