400 TPS and “Ethereum on your phone”: Vitalik Buterin & Tomasz K. Stańczak dropped big news at ETHKyiv 2025

The following is a guest post and opinion of Rostyslav Bortman, Founder of Ethereum Ukraine.

Even in wartime Kyiv, innovation doesn’t pause. At ETHKyiv 2025, more than 100 hackers proved it—shipping privacy-first dApps, competing for grants, and showing what’s possible when the world’s toughest challenges meet Web3 grit.

But the real shockwaves came from the founders themselves: Vitalik Buterin and Tomasz K. Stańczak, Executive Director at the Ethereum Foundation, who both appeared as the event’s online speakers, dropped two bombshells—400 TPS on Ethereum L1 this year, and a near future where anyone can run a full node on their smartphone.

So what’s next for the protocol? When does 400 TPS arrive, and what does “Ethereum on your phone” actually mean for developers and users? Here’s what we learned at ETHKyiv 2025.

Next-Gen UX: Nodes on a Phone

Vitalik Buterin’s keynote at ETHKyiv 2025 cut straight to Ethereum’s core roadmap. The biggest reveal:

“Pretty soon you’ll be able to spin up a node on your smartphones and even smartwatches.”

According to Buterin, instead of relying on servers with terabytes of storage, soon users will be able to run a full Ethereum node “without heavy-duty resources.” This first-of-its-kind case will be possible thanks to zero-knowledge Ethereum Virtual Machines (zkEVMs) that the Ethereum Foundation is currently implementing.

zkEVMs are making nodes drastically lighter, cutting storage through verifying transactions without revealing and importing any information about them.

On Ethereum’s L2s, zkEVMs already cut transaction costs by up to 90% and settle in their finality under three seconds. Buterin said the next step is bringing these improvements to the Ethereum mainnet, making blockchain interactions on it as fast and affordable as traditional web applications.

400 TPS with 3-Slot Finality by 2026

At ETHKyiv 2025, Tomasz K. Stańczak, Co-Executive Director of the Ethereum Foundation, spelled out exactly what’s next for Ethereum’s backbone: real performance gains on the mainnet itself.

He revealed that by the end of 2026, Ethereum will move to 3-Slot Finality (3SF), slashing average transaction confirmation time from 15 minutes down to only 36 seconds. For users, this will bring the experience of instant traditional digital payments while keeping all the benefits of decentralization.

Stańczak laid out the near-term milestones:

Ethereum L1 will hit 400 transactions per second (TPS) by the end of 2025.

Block gas limits will reach 100 million this year, with a jump to 60 million per block in a month or two (as of publication date—ed.).

For context: scaling Ethereum L1 is essential because it anchors the entire ecosystem, providing the security, settlement, and censorship resistance Layer 2s depend on. With faster mainnet throughput, users get greater assurance their transactions are finalized on a decentralized, global network—not bottlenecked by L2 operators.

As Vitalik Buterin summed up:

“The goal is to make Ethereum more private, more censorship-resistant, and at the same time, so easy that even people far from tech feel safe using it every day.”

What’s Really Fueling Ethereum’s Value and Mass Adoption?

For me and all the Ethereum followers, some big questions have always remained: what actually underpins Ethereum’s value, and what could trigger mass adoption?

When I pressed both Vitalik Buterin and Tomasz Stańczak for answers at ETHKyiv 2025, they each zeroed in on different but connected drivers.

Tomasz pointed to three non-negotiables: privacy, data protection, and transparency. According to him, these are precisely what enterprise clients and regular users now expect from any blockchain platform.

“Ethereum is a global network, and increased adoption directly boosts the value of the whole ecosystem,” he explained.

The more Ethereum is used for real-world utility—by businesses and by individuals—the more demand, and ultimately, value accrues.

Vitalik, meanwhile, framed the adoption question around financial utility. His thesis: mass adoption comes when Ethereum becomes the rails for real-world assets, particularly tokenized stocks and bonds.

“They’re the gateway to mass adoption and the bridge between traditional finance and Web3,” he said.

With heavyweights like BlackRock, Deutsche Bank, and Coinbase actively leveraging Ethereum for asset tokenization, we’re already seeing the lines blur between traditional finance’s $117 trillion market and Web3 infrastructure.

In short: Ethereum’s real value isn’t just speculative, but it’s being built right now at the intersection of security, privacy, and practical financial applications. That’s where mass adoption starts to look inevitable.

Why ETHKyiv 2025 Matters for Ukraine and Beyond

ETHKyiv 2025 indeed stood out for its access to global thought leaders. Despite all the war-related risks, developers here heard first-hand insights from Ethereum’s most influential builders.

As Stańczak himself described it:

“Enterprise, DeFi, explorations, AI, research, day-to-day problems, working with people—we have to understand the direction and give feedback. A lot of it.”

His daily routine—hours spent answering questions from developers—underscores how Ethereum’s power lies in its people, not just its protocol.

Crucially, ETHKyiv 2025 was never just another tech event on the calendar. Held against the backdrop of an ongoing war, it became living proof of something bigger: even in the darkest times, Ukraine’s tech community chooses to build, learn, and connect with the global ecosystem.

Throughout the hackathon, the wartime context was impossible to ignore, yet it wasn’t a shadow but a driving force. Performances by Moisei Bondarenko, the violinist-soldier whose music echoes through liberated Ukrainian cities, reminded everyone that innovation and humanity must go hand in hand. So did the tactical medicine session led by combat medic Artem Rudy, bringing practical skills and a sense of shared resilience to the room.

This is what set ETHKyiv 2025 apart: it was a gathering of minds and hearts, a testament to the persistence of community, curiosity, and shared values—even in wartime. The world watched not just for the tech, but for the spirit of resilience and solidarity that Ukraine’s builders brought to the stage.