Ethereum scaling solution Optimism delays its mainnet launch at least until July

Ethereum Layer 2 scaling solution Optimism has delayed the public launch of its mainnet.

The mainnet was scheduled to roll out this week, but it has now been postponed at least until July. The new schedule is just a rough estimate, said Optimism, because the launch is a "collaborative effort" of the Ethereum community.

"Opening mainnet to the public is not something we can do alone," said Optimism. "It will be a collaborative effort between us, projects, and core infrastructure providers like oracles, wallets, nodes & explorers."

So when the ecosystem is ready and there is stability, Optimism will launch its mainnet to the public.

Optimism has been building an Optimistic Rollup-based Ethereum scaling solution since June 2019. The solution aims to increase Ethereum's throughput (the number of transactions processed per second) and reduce its gas fees.

Earlier this year, Optimism "soft launched" its solution — the Optimistic Virtual Machine (OVM) — with decentralized exchange Synthetix. That means Synthetix will integrate the solution in four phases to limit risk to its platform.

Optimism said Synthetix users have already been enjoying speed and cost savings. Around $10 million have been saved on fees across more than 100,000 transactions, said Optimism.

Another major decentralized protocol set to integrate with Optimism is Uniswap. Earlier this week, Uniswap said it targets an L1 Ethereum mainnet launch of its version 3 (V3) on May 5, and an L2 deployment on Optimism will follow "shortly after."

Optimism, formerly known as Plasma Group, has pioneered Optimistic Rollups. A rollup provides scaling by bundling or rolling up transactions into a single transaction. With rollups, a transaction is received on the main Ethereum blockchain, but it is executed on a Layer 2 solution, and the execution data is then sent back to Ethereum. Since computation is done off-chain, it reduces Ethereum's load but maintains its security.

Another variant of rollups is ZK-Rollups. Both Optimistic Rollups and ZK-Rollups have their pros and cons, but the main difference between the two is that the former uses fraud proofs, and the latter uses validity proofs. Thus, with Optimistic Rollups, a transaction can be challenged, but not with ZK-Rollups. With ZK-Rollups, transactions are valid by design.

Ethereum creator Vitalik Buterin recently said rollups are a "powerful" solution for Ethereum scaling in the "short and medium-term future (and possibly long-term as well)." But they are still an early-stage technology, Buterin said, suggesting that more work needs to be done in the years to come.

StarkWare and Hermez are two of several projects that have built ZK-Rollups-based scaling solutions. StarkWare's clients include dYdX and DeversiFi, and Hermez's clients include Tether and others.