Statsig has introduced updates to its Stats Engine used in Pulse, aimed at improving the accuracy and clarity of experimental analysis. The major changes include shifting the unit of analysis from a user-day to a user, and adopting Welch's t-test for small sample sizes, which enhances the confidence intervals and reduces biases in both long-term and small-scale experiments. This update has been applied to all ongoing and future experiments, with past experiments retaining the old engine's results. While most results remain unchanged, some may experience a shift in statistical significance. Additionally, the new engine reduces false positive rates but limits flexibility in date range selection, offering predefined time windows and customizable queries for data analysis. Statsig continues to seek user feedback and engagement to further refine their tools and supports inquiries through various communication channels.