Rollups launched via AltLayer's RaaS are operated by a decentralized sequencer network. These sequencers are selected from a shared sequencer network called the Beacon Layer based on their stake and some randomness.
Beacon Layer is a network of nodes open for anyone to join and in fact a full-fledged blockchain in itself with WASM as well as EVM runtimes. The nodes in the Beacon Layer are called validators, typical of any PoS network. Once a validator becomes a part of the Beacon Layer network, it can be chosen to become a sequencer for a rollup instantiated by AltLayer’s rollup-as-a-service solution.
AltLayer recommends having at least 5 sequencers for each rollup and therefore for each rollup, at least 5 distinct validators from the Beacon Layer are selected.
Beacon Layer supports WASM as well as EVM implemented in WASM, however, it is not designed to execute arbitrary smart contracts for end users. Instead, the network’s main responsibility is to aggregate all the sequencers to one dedicated network and later select and assign its validators as the sequencers for a rollup. The network also provides a soft confirmation before the rollup transactions achieve finality from the Layer 1.