Leios, A Major Milestone in Cardano's Scalability Push

English Research & Development
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Leios, A Major Milestone in Cardano’s Scalability Push

Cardano’s journey toward lightning-fast scalability just took a big step forward with the release of the Ouroboros Leios CIP (Cardano Improvement Proposal) draft. Leios is built to supercharge transaction throughput on the mainnet, tackling those frustrating congestion spikes where blocks often hit over 90% utilization. This bottleneck slows down everything from airdrops and oracles to DEXes and DApps, but Leios flips the script with a smart decoupled system: it separates block production from aggregation, ramping up input-block creation, streamlining endorsements, and locking everything securely onto the main chain. In short, it breaks through the limits of Ouroboros Praos without missing a beat.

Think of it like a busy highway during rush hour: Current Cardano is like a two-lane road where cars (transactions) pile up and slow everyone down. Leios adds “express lanes” for faster processing, letting more cars zoom through without causing crashes or centralizing control—resulting in smoother, quicker trips for all drivers (users, SPOs, and devs).

Supercharging Performance and Long-Term Viability

Through rigorous research and simulations, Leios shows it can crank up throughput by 30 to 60 times compared to Praos—hitting key targets for economic sustainability as Cardano’s reserve rewards taper off. Our R&D team dove deep into design choices, weighing trade-offs like speed, rollout timing, ecosystem ripple effects, and staying ahead of the competition. The CIP lays it all out: a clear spec, solid reasoning, and hard evidence from Haskell and Rust simulations that test real-world scenarios, including tough adversarial attacks.

The Handover and What’s Next

This milestone paves the way for a smooth handover from the R&D and Innovation team to Input Output Engineering (IOE), where Sebastian Nagel and his crew will lead the charge on implementation starting soon. Looking ahead, we’ll tackle detailed node specs, network prototypes, big-scale testing, and even roll out a dedicated Leios testnet so the community can jump in, test, and help refine it.

For the full details, check out the CIP draft and Leios resources on cardano-scaling.org.

Resources

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FYI - Updated link for the CIP – CIPs/CIP-0164 at leios · cardano-scaling/CIPs · GitHub

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thanks @Kris_Bennett for spotting that — we don’t get CIP PRs linked from the Cardano Forum as much as we used to, so I’ll try to remember to check for these when the GitHub pathnames change: which must happen at least once when a CIP number is assigned. :nerd_face:

For all interested parties and potential reviewers: at this stage (and afterward, as evidence of peer review) the review commentary should be considered as much a vital part of this proposal as the document itself. So if you have a stakeholder interest, or want to know further detail about how this standard is developing, please also read the review thread and contribute your own review if appropriate:

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