In today's digital age, businesses rely on services and products to function seamlessly, with minimal downtime expected from these systems. Uptime is defined as the time when something is operational, but it can be measured in different ways, resulting in a spectrum of functionality. Measuring uptime is often done using nines, where each nine represents exponentially harder to achieve, such as 90% (one nine), 99% (two nines), and 99.9% (three nines) uptime. Four and five-nines require more validation and automation, and companies with these levels of uptime have a carefully cultivated engineering culture that encourages high quality and accountability. To improve uptime, developer teams can focus on error prevention and awareness, such as code validation and checks, automated testing, canary deploys, and application monitoring, which provide real-time insights into service health and alert developers to issues immediately. By implementing these strategies, businesses can minimize downtime and resolve issues quickly, ultimately improving service uptime.