The Tezos mainnet activated the Ushuaia upgrade on June 30, 2026, at 00:31:52 UTC, hitting block 13,857,889. The upgrade roughly 15x the bandwidth of the Data Availability Layer (DAL) — from about 0.66 MB/s to 10 MB/s — and cut finalization times for DAL confirmations from roughly 66 seconds down to 12–18 seconds when 66% of attesting power confirms. The release also ships the scaffolding for sTEZ, a liquid staking token, though the feature itself won't go live on mainnet until a future Protocol V upgrade.
Faster data, faster finality
The DAL bandwidth jump means rollups can push through more data per second. That translates to higher throughput potential and a better user experience, especially for applications that rely on quick data availability. The old system waited for a fixed number of blocks before finalizing; Ushuaia replaces that with dynamic attestations, so confirmations happen as soon as enough attesting power signs off. Bridges, exchanges, and app UX stand to benefit most from the latency drop from 66s to 12–18s.
Builders can now increase batch sizes, but the upgrade doesn't remove all constraints. Sequencer limits and attester participation rates remain bottlenecks that could cap the real-world speed gains.
What sTEZ brings — and what it doesn't yet
Ushuaia introduces sTEZ behind a feature flag. It's an FA2.1 token whose exchange rate to XTZ increases as staking rewards accrue — a classic liquid staking design. Testnets are already live, but mainnet activation isn't part of this upgrade. Only the scaffolding shipped: the code and infrastructure needed to eventually turn on sTEZ. The team behind the upgrade has targeted mainnet sTEZ for a later Protocol V upgrade, though no date has been set.
For now, users can't mint or trade sTEZ on mainnet. The feature flag means the logic is dormant until a future vote or governance process flips it on.
Bottlenecks that remain
Even with faster DAL finalization, the upgrade doesn't solve every throughput problem. Sequencer limits cap how many transactions a rollup can order per second, and attester participation — the percentage of validators that actually attest to data availability — can fluctuate. If participation drops, the 12–18 second finality window could stretch. The upgrade gives builders more room, but it doesn't guarantee they'll fill it.
The next concrete milestone is the Protocol V upgrade, which will decide whether sTEZ goes live on mainnet. No timeline has been announced, but testnet results will likely shape that decision.
