Chaos Engineering is a discipline that involves intentionally triggering failures in a controlled environment to enhance the reliability of complex web systems by identifying hidden weaknesses before they occur in production. Originating from practices formalized by Netflix, such as the development of Chaos Monkey, Chaos Engineering goes beyond traditional failure testing by conducting controlled experiments to explore unpredictable system behaviors under stress, such as server failures and traffic spikes. These experiments involve comparing a system's steady state to its behavior during simulated real-world events, allowing engineers to address potential vulnerabilities. A critical aspect of Chaos Engineering is its focus on learning from failure, as demonstrated through practical examples like simulating the unavailability of a MySQL database to uncover system dependencies and misconfigurations. Gremlin, a company specializing in Chaos Engineering tools, emphasizes the importance of addressing known issues before conducting experiments and highlights the value of discovering new system properties to prevent catastrophic failures. The practice is presented as an essential approach to building resilient systems, encouraging organizations to start experimenting with Chaos Engineering to uncover and mitigate risks proactively.