Booking.com, a travel e-commerce giant, manages an enormous volume of metrics using Graphite, an open-source monitoring tool, to handle millions of metrics per second. Initially employing a stack designed in 2014, the company faced challenges such as single points of failure and inefficient data distribution, which they resolved by rewriting parts of the system, including a relay in C and transitioning to the Go programming language for better performance and maintainability. The company adopted the jump hashing algorithm to improve metric distribution and moved to using Kafka for data transmission, while also integrating Grafana for enhanced data visualization. Despite these advancements, Booking.com continues to refine its system with plans to replace the Whisper storage format due to its inefficiencies and explore new protocols like gRPC for better compression and performance. Smirnov, a former Booking.com employee, highlights the stack's adaptability and its usage by other companies, emphasizing the simplicity and scalability of their setup involving Grafana, Carbon API, and Go Carbon for efficient metric handling and visualization.