Vinod Bagal and Jagpreet Singh discuss the modernization of legacy databases to Java and MongoDB Atlas, emphasizing that such transitions need not compromise batch performance. By employing bulk operations, intelligent prefetching, and parallel execution, they developed an optimization framework that not only matches but often exceeds the performance of legacy systems, with some workloads seeing execution times improve by 10–15 times. The framework addresses common issues like high network round-trips and inefficient operations by leveraging MongoDB’s capabilities, resulting in significant performance gains for global insurance platforms and other industries. This enhancement offers the potential to support new functionalities and meet the demands of modern applications. The article advocates this approach as a viable strategy for organizations looking to modernize their systems, while also providing insights into the technical architecture and tuning tips to optimize performance further.