Worked on the phpstan-src repository over a two-month period, focusing on code quality and static analysis improvements in PHP. Delivered a targeted code refactoring by removing the unused shouldGeneralizeInferredType method from template type classes, simplifying internal logic and reducing future maintenance overhead. Enhanced type inference for the idate function by expanding the IdateFunctionReturnTypeHelper to support additional format identifiers, including day, hour, and month, and introduced new unit tests to verify correct return types. Leveraged PHP development and static analysis skills to improve maintainability and typing precision, supporting more reliable static analysis for PHP projects using phpstan-src.