The why?

To solve Ethereum’s scalability issues various solutions like zkEVM, Optimistic roll-ups (Optimism, Arbitrum) have popped up. But, in Fuel’s view all of them come with some sort of compromise often execution or security.

The how?

In 2020, Fuel v1 was built; first optimistic rollup on mainnet. They didn’t try to copy Ethereum’s EVM, instead opted for a simple UTXO (Unspent Txn Output) making it easier to compute fraud proofs. No sequencers or complex re-execution. Fuel v1 was referred to as the first and only ‘Pure State Machine’

Now, they look to build a Rollup OS w/ Fuel v2. They aim to solve 4 crucial bottlenecks:

1. Asset Handling:

Native protocol-level asset support, Tokens are contract based on Optimistic Rollups. In Fuel v2, asset operation is in-built happens at a protocol level — so no smart contract bs.

2. Security Model:

Assets inherit the security features at a protocol level by default. Whereas, Optimistic rollups are mainly at a contract-level. So, no reliance on third party auditors or fear of re-entrancy attacks.

This is because of UTXO which means all the state changes are atomic.

3. Scalability Architecture: Fuel V2:

Bottleneck in Optimistic rollup system is that all the execution is Sequencer/Sequential. Hence allowing one txn at once. Fuel v2 is enables parallelization — simultaneous txn processing. Whilst inheriting UTXO model for proofs from v1.

4. Future Adaptability:

It’s built with a flexible architecture that can easily incorporate future advances in EVM. Its purpose-built FuelVM, UTXO model, and modular components can be independently upgraded to support new features like ZK-proofs, improved consensus mechanisms, or novel data availability solutions.

This flexibility means devs won't need to significantly refactor their dapps whenever a new innovation pops up.