Worked on enhancing the robustness of JSON decoding type analysis within the phpstan/phpstan-src repository, focusing on improving static analysis accuracy for PHP codebases. Refactored the JsonThrowOnErrorDynamicReturnTypeExtension by replacing deprecated instanceof checks with more reliable type checking methods, which improved the handling of constant string types and the force array flag. This approach reduced false positives and negatives in type inference for JSON decoding operations, enabling safer and more predictable code changes. Utilized PHP, PHPStan, and static analysis techniques, with an emphasis on type hinting and refactoring to ensure maintainability and traceability through well-documented commits.