Impressions, clicks, and click-through rate per variant and language. Statistical significance via two-proportion z-test (p < 0.05). At least 30 impressions per language required for reliable results.
Methodology
• 50/50 random assignment via session cookie (30-day expiry).
• Impressions recorded via IntersectionObserver at 50% visibility threshold.
• Clicks recorded on onClick event before navigation.
• Two-proportion z-test; significance threshold p < 0.05.
• Data stored in-memory; resets on server restart.
• Active experiments: cta-hero (homepage hero), cta-header (site header).