Explore the evolution of Drupal's configuration management and validation in this 23-minute conference talk from DrupalCon Lille 2023. Dive into the journey from Drupal 8's introduction of concepts like "configuration", "configuration and content entities", "validation constraints", and "API-First" to the current developments in configuration validation. Learn about the challenges faced in modifying configuration through REST or JSON:API and how this has impacted the Drupal (JS) Admin UI initiative. Discover the groundbreaking work done in the background to validate configuration, including the use of contrib modules and recent implementations in Drupal core. Understand the significance of these advancements for eliminating configuration errors, improving Drupal's reliability, and supporting initiatives like Recipes. Gain insights into the practical applications of config validation, its current usability, and opportunities to contribute to its further development.