Worked on the thingsboard/langchain4j repository to deliver a code quality enhancement focused on centralizing null and empty checks throughout the Java codebase. The approach involved refactoring multiple classes to replace custom validation logic with standardized utility functions, specifically Utils.isNullOrEmpty and Utils.isNullOrBlank, thereby improving consistency and maintainability. This effort emphasized code refactoring and utility function implementation, reducing redundant runtime checks and consolidating validation logic for better readability and testability. No major bugs were addressed during this period, as the primary objective was to establish a unified validation pattern that supports easier onboarding and future enhancements across the project.