Requirements Engineering Challenges for Blockchain Rollups

Rollups are a type of blockchain network that derives state from another blockchain network. These systems are complex pieces of middleware that provide a development platform for decentralized applications but also depend on another blockchain network to function. They involve a number of components, some of which execute off-chain (possibly on specialized hardware), and some of which are implemented via smart contracts. They are expected to handle millions of dollars in cryptocurrencies and operate at scale with strong liveness guarantees. These properties result in a unique set of requirements for these systems. In this document, we report on the requirements engineering challenges related to building such a system from first-hand experience.