The goal of migrating transactional data to MongoDB in AWS with the Zaloni Arena Data Governance Platform is to improve scalability by moving a customer's entire transaction application from an on-premise SQL Server database to MongoDB Atlas, which was facing difficulty scaling its data environment at a rate matching daily ingestion of live data through its servers. The complexity of migrating high volumes of data efficiently from the relational database to AWS and MongoDB presented several challenges, including recognizing potential data complexities due to the customer's global customer base and dealing with large SQL server instances still in use. To overcome these challenges, Zaloni utilized the Arena platform to code, build, and orchestrate the data validation process, establishing a cloud-based data environment that could operate without human interaction and allowed the team to shift their focus on the remaining application migration. The project demonstrated the importance of creating a data validation process, accessing sample data before production starts, and utilizing the Zaloni Arena platform to manage incremental data at hand and provide necessary data transformations using AWS EMR.