During April 2025, Daniel Stefka enhanced the JustJirka/P6PP repository by developing a booking availability validation system to address double-booking issues. He implemented backend logic in C# that checks for overlapping service times, both for rooms and trainers, during service creation and updates. By integrating validation logic that raises exceptions when conflicts are detected, Daniel improved data integrity and reduced the need for manual conflict resolution. His work leveraged API development and database management skills to ensure that scheduling conflicts are proactively prevented, laying a foundation for more robust scheduling features and contributing to the reliability of the booking process.