During December 2024, rjf1138 developed two core features for the geultto/daily-solvetto repository, focusing on algorithmic problem-solving in Java. They implemented an itinerary routing solution using depth-first search and graph traversal to compute the lexicographically smallest route from a set of flight tickets, ensuring deterministic results through route sorting and robust edge-case handling. Additionally, they delivered multi-problem solutions, including a genre-based ranking system for the Best Album problem and a pattern-matching approach for identifying unique banned user combinations. The work demonstrated strong command of algorithms and data structures, with clear code organization and attention to correctness and maintainability throughout.