Arnout van der Knaap focused on backend development for the OpenConext/OpenConext-engineblock repository, addressing a critical issue in the Single Sign-On flow. He improved the reliability of Identity Provider auto-selection by correcting the decoding of the entityID from a JSON-formatted login cookie, which previously risked misrouting users during authentication. Working primarily with PHP, Arnout updated the parsing logic to ensure accurate extraction of the entityID, thereby aligning the IdP selection process with user intent and reducing login errors. This targeted bug fix enhanced the robustness of cookie handling and contributed to a more stable and user-friendly authentication experience.