Ethereum’s Fusaka and Glamsterdam Upgrades: A Deep Dive into ACDC Call #162

Ethereum’s developer community convened for the All Core Developers Consensus (ACDC) Call #162 on August 7, 2025, to tackle the nuts and bolts of the upcoming Fusaka upgrade and sketch out early plans for Glamsterdam. This wasn’t just a routine check-in—it was a high-stakes discussion on scalability, decentralization, and the messy reality of pushing blockchain tech forward without breaking everything.

• Fusaka Milestones: Devnet testing progresses with blob capacity scaling, eyeing mainnet activation on November 5, 2025.
• Glamsterdam Vision: EIP-7732 (ePBS) takes center stage to decentralize block building.
• Obstacles Ahead: Client readiness gaps and delay risks threaten tight timelines.

Fusaka: Scaling Ethereum’s Data Backbone

The Fusaka upgrade stands as Ethereum’s next big leap toward solving its scalability woes, zeroing in on data availability for layer-2 solutions. For those new to the game, layer-2 networks like Optimism and Arbitrum process transactions outside Ethereum’s main chain to cut congestion and fees, then settle the results back securely. But they need the base layer to store data cheaply and efficiently. Enter Fusaka, building on the proto-danksharding concept from the Dencun upgrade in March 2024. Proto-danksharding introduces “blobs”—temporary data chunks stored off-chain but verifiable on-chain—to slash storage costs for these rollups. The endgame? Make Ethereum capable of handling millions of transactions without choking on gas fees, a critical step for DeFi and NFT ecosystems hungry for growth.

Developers shared that Fusaka Devnet-3 is in the thick of finality testing, with 100% validator participation. They’re not holding back, simulating brutal scenarios like node failures, supernode removals, and bandwidth throttling (think choking 30% of nodes to 1 Mbps) to test client resilience under real-world pressure. On August 8, 2025, Devnet-4 launched to mimic 10% of mainnet scale for short, intense data collection—a stress test dialed up to eleven. Meanwhile, the blob capacity increase for scalability, or BPO, rolls out in phases to avoid a network meltdown. Starting at epoch 404480, it targets 6 blobs per block (max 9), scaling to a max of 72 by BPO5. This cautious ramp-up lets devs monitor stability, much like widening a highway while traffic’s still roaring through.

The timeline for Fusaka is aggressive: client releases for Holesky and Sepolia testnets on September 1, testnet forks on September 15 and 22, mainnet client release on October 1, and full activation on November 5, 2025. But not everyone’s ready to sprint. Client teams are out of sync—Prysm’s got heaps of unmerged code, Teku’s running on master, and Nimbus resists testnet-only releases. It’s like a relay race where half the team hasn’t tied their shoes yet. Matthew Keil from Lodestar raised red flags on spec finalization, pushing for a 4-week delay to squash integration bugs.

“Even a 1-month delay now could cascade into a 3-month delay due to the year-end holiday season,” warned Justin Traglia, driving home the urgency of sticking to the plan.

Risks and Roadblocks for Fusaka

Delays aren’t just a minor hiccup—they’re an Ethereum tradition. Look at The Merge, pushed back repeatedly before landing in 2022. A slip in Fusaka’s timeline challenges could stall layer-2 momentum right when DeFi users and NFT creators are begging for cheaper transactions. As Traglia pointed out, holiday slowdowns could turn a small stumble into a long winter of discontent. On the flip side, rushing an undercooked upgrade risks network chaos. Remember the DAO hack of 2016? No one’s eager for a sequel. Developers are caught between a rock and a hard place: push too fast, and nodes crash under untested blob loads; wait too long, and the community loses patience.

Other technical tidbits from the call hint at both promise and peril. A proposal (PR #546) to enhance the Beacon API with a getBlobs endpoint aims to ease blob data access and lighten node strain, though the design’s still up for grabs. Another tweak (PR #4476) swaps hardcoded slot timing for basis points, making Ethereum’s internal clock more flexible. This ties into EIP-7782’s bold pitch for 6-second slots—down from 12—to speed up confirmations. Sounds sexy, sure, but if nodes lag, it’s a disaster waiting to happen. Thankfully, network metrics offer a glimmer of hope. Block propagation now clocks under 1 second, and attestation delays at the 95th percentile dropped from 2.52 to 1.85 seconds.

“These new figures ‘look better than last time,’” noted Alex Stokes, signaling cautious confidence in Ethereum’s ability to handle heavier loads.

Still, let’s not ignore the broader scope of Fusaka. Beyond blobs, EIPs like 7825 (raising gas caps to 30 million per transaction) and 7907 (boosting contract code size to 256KB) didn’t make the call’s highlight reel but are in play. These could unlock wild new DeFi apps, but without tight gas cost controls, they’re an open invite for denial-of-service exploits. Are devs cherry-picking priorities or just drowning in feature bloat? It’s a question worth chewing on.

Glamsterdam: A Decentralized Horizon

While Fusaka grabs the immediate spotlight, Glamsterdam—tentatively slated for 2026—got its share of airtime as the next frontier. The lead feature, EIP-7732 or enshrined Proposer-Builder Separation (ePBS), took center stage. So, what’s ePBS? It splits the roles of block proposers (who select transactions) and builders (who assemble blocks) to prevent centralized control over block production. This tackles a nasty issue called MEV, or Miner Extractable Value, where miners—or now builders—reorder transactions for profit, often screwing over users. ePBS curbs this by making the process fairer and more decentralized, a move that even Bitcoin maximalists might nod at for echoing the ethos of resisting centralized power.

Compare that to Bitcoin, where mining decentralization remains the bedrock, and Ethereum’s ePBS focus on decentralization feels like a kindred spirit, even if wrapped in layers of complexity. But it’s not all rosy. Implementing EIP-7732’s challenges could introduce bugs or new centralization vectors if not battle-tested. Meanwhile, EIP-7805 (FOCIL), focused on cross-layer optimizations, got sidelined to “consider for inclusion” due to its technical headaches. This cautious stance reflects Ethereum’s playbook: innovate hard, but don’t shatter the network. Historically, MEV has been a thorn in Ethereum’s side since DeFi’s boom, with centralized builders exploiting transaction ordering. Glamsterdam’s vision with ePBS signals a push to reclaim fairness, but the road’s long and bumpy.

Ethereum’s Complexity: Strength or Achilles’ Heel?

Zooming out, Ethereum’s relentless upgrade cycle—Fusaka, Glamsterdam, countless EIPs—stands in sharp contrast to Bitcoin’s “keep it simple” mantra. Bitcoin sticks to being a rock-solid store of value, while Ethereum’s playing 4D chess with scalability, DeFi, and NFTs. That’s a strength, filling niches Bitcoin sidesteps, but also a glaring liability. Over-engineering could bog Ethereum down in delays and bugs, unlike leaner altcoins like Solana or Avalanche, which tout faster, simpler scaling (though often at security’s expense). Is Ethereum’s complexity a visionary edge or a self-inflicted wound? As champions of effective accelerationism, we back the drive to disrupt centralized finance, but damn, sometimes it feels like Ethereum’s tying itself in knots while Bitcoin just chugs along.

Then there’s the corporate shadow. Layer-2s like Arbitrum, heavily VC-backed, raise eyebrows. Are we decentralizing finance or just swapping old banks for new tech overlords? Fusaka’s blob scaling could turbocharge these rollups, slashing fees for the average DeFi user or NFT artist, but if governance stays centralized, it’s a hollow win. We’re all for pushing tech forward fast, but not at the cost of the freedom and privacy blockchain promised.

What’s Next for Ethereum’s Revolution?

The ACDC Call #162 insights paint Ethereum at a pivotal juncture. Fusaka’s November 5, 2025, target looms, but delays lurk like an uninvited guest. Glamsterdam’s ePBS offers a shot at true decentralization, yet technical minefields abound. We’re rooting for Ethereum to disrupt traditional finance with scalable, decentralized tech—layer-2 adoption could redefine money for millions. But let’s not buy the hype wholesale. Client teams must sync up, testing needs to be airtight, and the community should brace for turbulence. Ethereum’s carving a path Bitcoin doesn’t tread, vital for the crypto revolution’s breadth. If they stumble on their own complexity, though, it’s not just their loss—it’s fuel for every skeptic doubting blockchain’s power to remake the financial world.

Key Questions and Takeaways

• What is the Fusaka upgrade and why does it matter for Ethereum?
  Fusaka, targeting mainnet activation on November 5, 2025, expands proto-danksharding with blobs to cut data costs for layer-2 rollups, making transactions cheaper and scaling Ethereum for millions of users in DeFi and NFTs.
• What are Ethereum blobs and how do they help scalability?
  Blobs are temporary off-chain data chunks, verifiable on-chain, introduced in proto-danksharding to store layer-2 data cheaply, reducing mainnet congestion and slashing transaction fees for rollup users.
• Why are timeline delays a major concern for Fusaka?
  Client readiness gaps and unmerged code risk bugs, and as Justin Traglia warned, a one-month delay could stretch to three over holiday slowdowns, stalling layer-2 growth at a critical time.
• How does Glamsterdam’s ePBS push decentralization forward?
  EIP-7732 (ePBS) separates block proposers and builders, curbing centralized control and MEV exploitation, aligning with Bitcoin’s resistance to power concentration and enhancing fairness in transaction ordering.
• Can Ethereum balance rapid innovation with network stability?
  It’s a tightrope—Fusaka’s blob scaling and Glamsterdam’s ePBS drive progress, but rushed upgrades risk crashes, while delays frustrate adoption. Historical stumbles like The Merge show the stakes.
• Is Ethereum’s complexity a risk compared to Bitcoin or other altcoins?
  Yes and no. Ethereum’s intricate upgrades enable DeFi and NFTs, unlike Bitcoin’s simplicity as a store of value, but overcomplication could breed delays, while Solana’s speed tempts users despite security trade-offs.
• What’s the real-world impact of Fusaka for crypto users?
  If successful, Fusaka’s cheaper layer-2 transactions could make DeFi trading and NFT minting affordable for everyday users, accelerating Ethereum’s role as a hub for decentralized finance.