Building a Telegram bot that allows administrators to view and modify currency rates and cross rates. This includes user authorization for specific users and integration with an existing API for synchronization. Extensive testing will be required to ensure proper functionality.

Redesigning the admin panel to create an easy-to-use table layout that separates primary rates from cross rates. Adding features for quick editing without navigating to a separate page and including an 'Update All Rates' button along with the last updated date feature. Thorough testing will be necessary for these updates.

Reviewing and correcting the logic of the currency conversion calculator to ensure accurate calculations across all currencies and cross rates, synchronizing with current rates from the database, and ensuring proper rounding of results. Testing is critical to affirm the accuracy of the fixes made.