SonarLint telemetry has identified common issues in Java projects, including commented out code, TODO tags left in source code, duplicated string literals, high cognitive complexity of functions, and unused elements that need to be removed from the codebase. These issues can impact software security, performance, maintenance, team collaboration, and readability, but many are easy to address with minimal effort. By implementing these best practices, developers can improve the intentionality, consistency, adaptability, and maintainability of their code, reducing the likelihood of errors and making it easier to refactor and evolve the codebase over time.