The Cardano ecosystem is nearing a major milestone as the major scaling upgrade Leios moves closer to its testnet launch targeted for the end of June.
In a recent discussion, Carlos Lopez de Lara, product manager at Input Output, breaks down how Leios, a scaling breakthrough, unlocks massive throughput and locks in Cardano’s network’s long-term sustainability.
Leios is a scaling solution for Cardano, utilizing the time between blocks to create an additional type of block called an endorser block. This additional type of block is a longer type that can carry far more transactions than a normal block can contain.
The road to Cardano 2030 runs straight through Leios, and the testnet goes live this week. @lilybrodi and @cwpaulm interview @carloslodelar, who breaks down how this scaling breakthrough unlocks massive throughput and locks in the network’s long-term sustainability. pic.twitter.com/xBjDQnmtiF
— Input Output Group (@IOGroup) June 22, 2026
Leios has the potential to scale Cardano from its current throughput of 4.5 KB/s to a staggering 200 KB/s. This will, however, be gradual.
Lopez de Lara highlights the need for a slow start, as a rapid increase might imply additional costs for SPOs, which is not needed at the moment. In this light, a 2x or 5x increase might be feasible, although the infrastructure for massive scaling will be there. According to him, Leios remains essential in reaching 27 million monthly transactions projected for 2030 and ensuring long-term network sustainability through transaction fees.
Another reason why Leios remains essential is the economic aspect. Lopez de Lara noted that the reserves are depleting and for the Cardano network to be sustainable in the long run, transaction fees need to be sufficient.
Leios testnet launch imminent
Lopez de Lara noted that the Leios testnet is due to launch at the end of June, but this isn’t just a typical launch. This testnet marks an important milestone as it serves as an intermediate step between its original research paper dating back three years ago and the mainnet launch anticipated by the end of the year.
The prototype implementation will be on the testnet, marking the first time that Leios will hit the real world.
The testnet is named Musashi Dojo, after the legendary samurai Miyamoto Musashi, and is structured into five distinct phases: Earth, Water, Fire, Wind, and Void.
The first phase, Earth, refers to basic protocol design validation. The next phase is Water, where the protocol parameters will be explored. The next phase is Fire, where Leios meets real-world conditions.
This is the most critical part for SPOs to get onboarded amid vast testing of software, operating systems, architectures, and hardware. The Wind phase is where adversarial testing takes place. The last phase is Void, where Leios is essentially getting ready for the mainnet launch anticipated by the end of the year 2026 or heading into 2027.
