In a world where different types of blockchain are emerging all the time, interoperability between them becomes essential. In the context of Drex, it will be no different. In this context, the workshop “Interoperability between Besu and Fabric with Hashtime Locked Contracts” aims to explore the concept of atom swaps and hashtime lock contracts between a Hyperledger Besu network and a Hyperledger Fabric network. The workshop will be divided into a conceptual and a practical part. This dual approach will allow participants to develop solutions based on the acquired knowledge.