Over a two-month period, Alex Dev updated the symfony/symfony-docs repository to document the new NumberNormalizer in Symfony 7.3, clarifying how BcMath\Number and GMP values are normalized as strings. He ensured the documentation matched code changes and changelogs, improving upgrade guidance for developers. In the symfony/symfony and symfony/serializer repositories, Alex addressed PHP 8.5 warnings by refining XML serialization logic, encoding NaN and INF values correctly and expanding unit tests to cover these cases. His work demonstrated strong PHP backend development, technical writing, and testing skills, resulting in more robust documentation and reliable serialization behavior across Symfony components.