The major events organized here mainly have two aspects:

• The first is the upcoming Eth1/Eth2 upgrades: Berlin (April), Altair (June), London (July), and Shanghai (second half of 2021).
• The second is expansion. The route chosen by Ethereum is to use rollup technology at the beginning (this year) (there are many types, please see below), and the next year is sharding.

The events listed below are not complete, only the more well-known ones have been selected.

Event line

All dates have elements of my guess, please don't treat them as time promised by the team.

First quarter of 2021 (January to March)

• March 18-Rocketpool final beta test. in progress.
• March 24-Hermez goes live. Now Tether can be cast on the second layer of the Ethereum network.
• March 24th-Eth1 Rinksby testnet Berlin upgrade. The final stage of testing before April 14. Everything is in plan.

The second quarter of 2021 (April to June)

• April 14th-Eth1 Berlin upgrade. Track progress here.
• Mid-April-RocketPool mainnet launch. Decentralized pledge service!
• April-The next stage of Immutable X goes online-open the market. It means a lot to NFT.
• April-The first bridge of Optimism / DAI. Cancel the first phase of the 7-day optimistic rollup withdrawal lock-up period.
• April-Coinbase pledge service goes online and the company goes public
  Late April-Optimism public testnet goes online.
  April-Arbitrum optimistic rollup mainnet (according to their announcement of v4 candidate testnet)
• April-zkSync 1.x tradeable tokens in the second-tier network.
• May-Uniswap v3
• Mid-May-Uniswap launches optimistic rollup. Hayden said in this tweet that it will be May 12th.
• May-zkSync 2.0 goes online on the public test network
• May-zkSync 1.x NFT casting and transfer
• June-Altair-Eth2 beacon chain / client upgrade, formerly known as HF1
• June 15-Pass / Fail Hawaii 2022
  The detailed specification of the merger. The normative PR already exists!
• Synthetix v3/ Synthetic Token Exchange on Layer 2-SNX/ Optimisim Migration Phase 1
• Connext P2P network release
  -StarkNet planetary phase is released. Single App Rollups

Third quarter of 2021 (July to September)

• July-London upgrade-Eth1 upgrade, incorporating EIP-1559 and ice age delay
• July-Optimism public mainnet launch
• August-zkSync 2.0 mainnet released. Achieve zk rollup of 20,000 transactions per second.
• Eth1/Eth2 combined product testing.
• Optimsim realizes fast withdrawal through MakerDao
• StarkNet constellation stage is released. Zk rollup of multiple apps
• Argent uses zk rollup to achieve two-layer expansion

The fourth quarter of 2021 (October to December)

• Shanghai upgrade-Eth1/Eth2 merger possible
• StarkNet universe stage is released. Decentralized zk rollup.