First, isolate the hot path – keep the code minimal, avoid any blocking calls, and use async where possible. Second, add redundancy at the infrastructure level: replicas, read‑writes split, and a fast failover. Third, instrument everything – logs, metrics, and alerts – so you know when a component starts to degrade and can roll back or scale before the error propagates. Finally, run continuous performance tests in a staging environment that mirrors production; that way you can catch bottlenecks before they hit real users. Keep the system lean, keep the checks tight, and you get speed without sacrificing reliability.