During peak traffic times, like holidays or seasonal sales, checkout errors can lead to significant revenue loss. To prepare for these high-stress periods, e-commerce businesses need robust error and performance monitoring systems in place. The article outlines a checklist to ensure readiness, which includes implementing error monitoring to capture and analyze issues in real-time, prioritizing fixes with smart alerting to minimize noise, and collecting user feedback to understand the customer experience. Error monitoring is critical. It allows businesses to track exceptions across critical systems like checkout and payment, helping to identify payment failures or other high-impact errors quickly. Smart alerting filters out less important issues and routes critical alerts to the right personnel. For instance, significant payment errors trigger immediate notifications, while lower-severity issues can be addressed later. The user experience can be improved through session replays, which show exactly how customers interact with the site, allowing teams to debug issues effectively. Performance optimization is also essential; even a slight delay can drastically reduce conversion rates. Using tools like Real User Monitoring, businesses can analyze real-world performance and identify slow areas, such as database queries or third-party scripts, that could impact user experience during traffic spikes. Lastly, implementing AI for code reviews can help catch potential bugs before they reach production, streamlining the development process and reducing the likelihood of errors during critical sales periods.