The Cardano network is approaching a key milestone as its Leios scaling upgrade targets a testnet release by the end of June. Carlos Lopez de Lara, product manager at Input Output, outlined how Leios could dramatically boost throughput and ensure long-term sustainability.
How Leios Works
Leios is a scaling solution that introduces an endorser block type, created during the time between regular blocks. These endorser blocks are longer and can carry significantly more transactions than standard blocks. The upgrade aims to increase Cardano's throughput from the current 4.5 KB/s to as much as 200 KB/s, though the rollout will be gradual.
Lopez de Lara emphasized the need for a slow start to avoid imposing additional costs on stake pool operators (SPOs). An initial 2x or 5x increase is considered feasible, with the infrastructure for massive scaling in place. Leios is seen as essential for reaching the projected 27 million monthly transactions by 2030 and maintaining network sustainability through transaction fees as reserves deplete.
Testnet Phases and Timeline
The testnet, named Musashi Dojo after the legendary samurai Miyamoto Musashi, is structured into five phases: Earth, Water, Fire, Wind, and Void. Earth focuses on basic protocol validation, Water explores protocol parameters, Fire tests real-world conditions—critical for SPO onboarding—Wind involves adversarial testing, and Void prepares for mainnet launch.
Lopez de Lara noted that the testnet launch is not just a typical rollout but an intermediate step between the original research paper from three years ago and the mainnet launch. The mainnet is anticipated by the end of 2026 or early 2027. This marks the first time Leios will be implemented in a real-world environment, moving from theory to practice.