Worked on enhancing dynamic form behavior in the hallowelt/mediawiki repository by implementing a new CONTAINS operator for HTMLForm conditional logic. This feature enabled hide-if and disable-if conditions to accurately evaluate multiselect field values, addressing the challenge of handling array-based inputs within forms. Using JavaScript and PHP, the solution ensured that conditional statements could check for the presence of specific items in array values, reducing incorrect UI states and improving user experience. The work demonstrated a focus on both back end and front end development, aligning technical improvements with product goals for more reliable and flexible HTML form interactions.