What is TN11 and how did it help prepare the Kaspa mainnet?

TN11 is a Kaspa testnet that operates at 10 blocks per second (BPS) and ran stably for over a year, demonstrating the network's readiness for the Crescendo Hardfork transition. A testnet is a live, separate copy of the network where developers can trial changes without touching real funds or the production blockchain. All of the Crescendo Hardfork changes — excluding KIP-13 and KIP-15 — were implemented and tested in TN11, producing real performance and stability data. For a beginner, this means the upgrade didn't just look good in theory; it ran in a live environment for more than a year before the Kaspa mainnet was asked to adopt it.