What are the key highlights of this year's Ethereum's most important upgrade, the Glamsterdam upgrade?

Ethereum founder Vitalik Buterin has been quite active on social media recently, first rethinking the previous Layer 2 direction roadmap, and then outlining a new plan for Ethereum's future.

This has raised the community's expectations for the Ethereum Glamsterdam upgrade in the first half of this year. What are the key contents of the Glamsterdam upgrade, the most important update for Ethereum in the first half of this year?

From the "Predecessor" to the "Successor"

Before understanding Glamsterdam, we need to understand its "predecessor" — the Fusaka upgrade.

Fusaka is a data layer upgrade for Ethereum. It introduced two key features: PeerDAS and EOF:

PeerDAS: Instead of downloading all data, only a small part needs to be downloaded. Similar to a sample survey where not everyone needs to be asked, just a small sample can infer the state of the entire group. Combined with ZK proof, even with only 1/16 of the data downloaded, data integrity can be confirmed, significantly increasing Ethereum's network throughput.

EOF: It can be understood as an internal reform of the EVM. It makes the EVM's code structure clearer, more modular, and easier to optimize. EOF is like giving the EVM a "renovation" to make its internal structure more logical.

If Fusaka is a "data layer upgrade," then Glamsterdam is an "execution layer upgrade." Fusaka mainly addressed "how to transfer data," while Glamsterdam aims to address "who will produce blocks."

The Core of Glamsterdam — ePBS and BAL

ePBS separates the block packaging and validation processes — block builders are responsible for packing transactions, proposers propose blocks, and validators validate blocks. Each role performs its duties, with the block builders able to more aggressively pack more transactions because proposers and validators help with checks, eliminating security concerns.

Can't Ethereum do this now? It can, but it relies on relays like Flashbots to separate "proposing" and "building." Validators only propose blocks, and builders pack transactions to earn MEV (Maximal Extractable Value).

This leads to a black box where trust in third-party relays may lead to faults, censorship, attacks, or centralization.

The ePBS has turned this mechanism of power separation into a built-in protocol (EIP-7732), transforming it into "on-chain auction + protocol enforcement," solving the trust issue and enhancing network efficiency.

The Block Access List (BAL) allows block producers to inform validators in advance: "The transactions in this block will access these accounts and storage locations." With this information, validators can prepare in advance, loading this data from disk into memory. Then, validators can concurrently check multiple transactions instead of one by one. It's like a factory assembly line: whereas one worker used to handle the entire product, now multiple workers process different parts simultaneously.

When these two are combined, it forms a dual reinforcement—efficiency improvement and resistance to censorship.

However, for the ePBS to achieve its full effect, it still needs another puzzle piece—Fork-Choice Obligated Inclusion List (FOCIL). FOCIL enables validators to publish a "must-include" transaction list. If the builder does not include these transactions, validators can reject the block through fork-choice rules. This gives validators the "last line of defense" to prevent over-censorship by builders.

However, launching ePBS and FOCIL simultaneously would bring considerable complexity. Therefore, the arrival of FOCIL needs to wait for this year's second upgrade, Hegotá.

Potential Impact of Glamsterdam

In addition to ePBS and BAL, Gas Fee Repricing + Multi-Dimensional Gas will also be included in the Glamsterdam upgrade, making transactions for ordinary users cheaper, once again increasing the network's overall capacity. However, this corresponds to a fee increase for some developers (those needing to build new states).

For stakers, the income model becomes clearer, block selection rights increase, and MEV returns become smoother. This also means that the MEV ecosystem will undergo changes, and some applications that rely on the existing ways to earn MEV may face adjustments.

With the increase in validator power, new application opportunities will emerge. For example, there may be new "validator service" applications to help validators better choose blocks.

However, the Glamsterdam upgrade is certainly not perfect. As mentioned earlier, although ePBS will come with the upgrade, it is still an incomplete version without FOCIL. The complexity of this update is quite high and grants validators more power. Besides the stability post-implementation, whether decentralization will lead to the formation of a new form of centralization at the validator level is also an area of concern.

Vitalik also acknowledged that "ePBS is only to prevent centralization among validators from spreading to the staking layer, but the centralization issue among block producers itself remains." The toxicity of MEV (sandwich attacks, front-running) may simply "move somewhere else" to continue.

However, in the long run, the biggest significance of the Glamsterdam upgrade may be "decentralization." Vitalik's persistence and idealism in decentralized theory may make traditional finance and even the world trust Ethereum's adoption more, and time may ultimately provide the true answer to this persistence reflected in Ethereum's price.

Since last year, Ethereum's major upgrades have increased to twice a year. No longer lying flat, Ethereum, which has started to "race against time," may indeed reshape its glory.