This document discusses the implementation of a core banking solution at Caja Popular Mexicana (CPMMX), a Mexican financial institution. The project involved converting customer account information from two existing systems into the new solution for 326 branches across 23 Mexican states. Key activities included data conversion and verification, user acceptance testing, pre-conversion preparation, and post-go live support. Challenges included issues with data quality, limited user testing time, and resource availability. The implementation team addressed these challenges by establishing dedicated teams, emphasizing communication and teamwork, and prioritizing customer needs.