Decentralized Finance (DeFi) leverages blockchain technology to provide financial services without intermediaries, relying on smart contracts to automate economic transactions. As of October 2025, DeFi protocols are estimated to manage over $100 billion in Total Value Locked, making them ideal targets for attacks. The complexity of DeFi protocols’ incentive mechanisms, combined with their entanglement in low-level implementation details, makes it challenging to precisely assess their structural and economic properties, analyse user strategies and attacks, and ensure that the code accurately reflects the intended functionalities. In this talk, we provide an overview of the different approaches used to study DeFi protocols - ranging from formal models to verification tools, as well as LLM-based methods - outline the main challenges, and discuss future directions.