Buildkite, a platform used by software development teams worldwide, undertook a comprehensive Reliability Review in early 2022 to address reliability incidents experienced in late 2021, aiming to enhance service reliability and better meet customer expectations. The review led to the establishment of Service Level Indicators (SLIs) and Service Level Objectives (SLOs) to monitor and improve service performance using tools like Datadog. A significant change includes the implementation of error budgets, where teams shift focus from feature development to reliability improvements when service performance falls short. The infrastructure was bolstered by adding a third AWS availability zone, and plans were made to transition the primary Postgres database to Aurora to address performance bottlenecks. These changes, alongside efforts to improve deployment processes and database efficiency, represent ongoing initiatives to maintain and improve Buildkite's service reliability, acknowledging that this effort is continuous and crucial for accommodating future growth.