This chapter examines the advanced technological pillars underpinning modern FinTech and their critical intersections with internet law and business. It analyzes how cutting-edge innovations—including AI-driven predictive analytics, blockchain smart contracts, quantum computing, decentralized finance (DeFi) ecosystems, big data, and immersive metaverse interfaces—are reshaping financial services. The discussion emphasizes both the transformative potential and the significant legal and regulatory challenges these technologies introduce, such as algorithmic accountability, data privacy, platform liability, cryptographic vulnerabilities, and the need for new compliance frameworks like RegTech. Ultimately, the chapter positions these technologies within the broader digital infrastructure, arguing that sustainable and ethical FinTech advancement depends on a co-evolution of technical innovation, robust legal governance, and trustworthy internet ecosystems.