The banking, financial services, and insurance (BFSI) sectors are considered the data-driven sectors that manage big data in large quantities intensively. Big data and FinTech technologies brought multiple drastic changes and advantages in the past two decades in the BFSI sector. Using these technologies, companies listed under BFSI have started offering customized products and services to the public through their innovative financially engineered services and products. Financial engineering (FE) includes designing and developing financially engineered products and services with the help of FinTech technologies along with other FE technologies. Notably, critical stakeholders of these sectors are enjoying the digital experience with an excellent and enhanced level of financially engineered services and products with big data applications. In financial markets, there are huge opportunities for data accumulation and precipitation. Thus, the authors have attempted to study the evolution, tools, and applications of big data and FinTech in the BFSI sectors, as well as FE applications and the emerging trends in the process. The scientific contribution of this chapter is how big data and FinTech technologies are used in the BFSI sector considering the emerging trends in the sector.