Charles Hoskinson: Leios Testnet Opens Cardano’s Biggest Scaling Phase

Charles Hoskinson said Ouroboros Leios is entering a live testnet phase, moving one of Cardano’s largest scaling upgrades into direct infrastructure testing. The testnet, called Musashi Dojo, is designed to validate the protocol through a staged process that includes basic design checks, parameter tuning, real world operating conditions, adversarial testing and final integration readiness.

The update followed the launch of Input Output’s new Block//45 podcast, whose first episode focuses on Ouroboros Leios. In the same remarks, Hoskinson described Leios as a broad protocol upgrade that affects Cardano’s ledger, network, incentive design and stake pool operations, making ecosystem coordination a core part of the path toward any future mainnet hard fork.

Musashi Dojo Sets a Phased Leios Testnet Path

Musashi Dojo organizes the Leios testnet into five phases named Earth, Water, Fire, Wind and Void. Earth focuses on validating the basic protocol design, while Water is used to explore and tune protocol parameters. Fire moves the protocol into real world testing across different hardware, operating systems and global operators.

Wind introduces adversarial testing, where the network is placed under hostile and extreme conditions. Void represents the final validation stage before mainnet readiness, including the point where third party integrations are expected to work through their own preparation.

Hoskinson said the first implementation path uses Linear Leios, which he described as a slight divergence from the original paper and an easier implementation route. The testnet gives stake pool operators, developers, exchanges, node operators and infrastructure teams a shared environment to begin testing before the final version reaches the hard fork process.

Leios Targets Higher Cardano Throughput Without Replacing the Core Model

Hoskinson said Cardano currently operates at about 4.5 transactions per kilobyte per second, while Leios is targeting about 200 kilobytes per second. He described that target as roughly a 44 times increase, with the early testnet phase expected to start at about 2 to 5 times current throughput before later phases show how the system can scale further.

The upgrade would place Cardano in the several hundred transactions per second range, according to Hoskinson, with a direct line of sight toward thousands of transactions per second. He also said the network currently runs at about 20% load or less, adding that Leios could provide enough base layer throughput for the next three to five years under aggressive Cardano growth assumptions, even without relying on Hydra or partner chains.

The technical relevance is not limited to performance numbers. Leios changes how Cardano prepares for higher throughput while keeping its existing design priorities around decentralization, security and infrastructure compatibility. That makes the testnet a proving ground for throughput, operator requirements, parameter safety and integration readiness at the same time.

Mainnet Timing Moves From Engineering Readiness to Network Coordination

Input Output’s internal target is to complete the full testnet work no later than November, if possible. Hoskinson said the development team can finish its part of the work, but cannot activate the hard fork on behalf of the Cardano network.

That distinction defines the next stage of the Leios roadmap. Cardano’s upgrade process now depends on the broader ecosystem accepting the final version, preparing infrastructure and moving through the appropriate governance and hard fork steps. Hoskinson said the size of Leios means some participants may choose to test longer before supporting mainnet activation.

Input Output plans to coordinate with the Cardano Foundation, Intersect, Pragma and other ecosystem actors to encourage early integration. Hoskinson also noted that recent Cardano hard forks have often taken several months from engineering readiness to activation, meaning a November development target could move into January or February if coordination slows. With Musashi Dojo live, Leios moves from a research and implementation track into a shared test environment where Cardano’s infrastructure can begin preparing for one of the network’s most significant protocol upgrades.