What to do if a test worsens metrics?

If metrics worsen as a result of an A/B test, it is important not to panic, but to conduct a thorough analysis:

• Check the correctness of the data and the statistical significance of the results.
• Analyze which specific metrics have deteriorated and why — perhaps the change affected user experience or technical stability.
• Assess whether external factors could have influenced the results (seasonality, marketing campaigns, etc.).
• If necessary, roll back the changes to avoid degrading the product for users.
• Learn lessons: understand what exactly did not work and use this knowledge for future experiments.

Thus, metric deterioration is a signal for analysis and improvement, not just a reason to abandon the idea.