Observability is the only way to engineer, manage, and improve the business-critical systems that customers depend on every day-and as the complexity of software grows, so does the need for observability. With this thoroughly revised second edition, authors Charity Majors, Liz Fong-Jones, and George Miranda take inventory of the current state of the field and explain how practitioners can evolve their observability practices from collecting separate, disparate signals to unified data workflows. This book is for any software engineering team, large or small, that must understand the unique customer experience in order to ship quality code and features that customers want, at the right velocity. You'll discover the value that observable systems bring and learn concrete steps you can follow to achieve an observability-driven development practice yourself. And four completely new chapters explore recent trends such as large language models, frontend observability, cost optimization/performance engineering, and practical open source tooling. Understand the impact observability has across the entire software development lifecycleLearn how and why different functional teams use observability with service-level objectivesImplement modern observability practices in your organizationMaximize the cost-effectiveness of observability toolingProduce quality code for context-aware system debugging and maintenanceUse data-rich analytics to quickly find answers when maintaining site reliability