Circle Internet Financial announced plans to transition its sandbox environment from the Ropsten to the Goerli Ethereum Testnet to enhance stability and reliability for developers. The Goerli Testnet uses a proof of authority consensus method, which offers greater stability compared to the proof of work models used by Ropsten, thereby minimizing disruptions in testing environments. The migration is scheduled from September 21 to September 23, 2021, during which the Ethereum network will be unavailable for testing in the Sandbox. Post-migration, Ropsten's on-chain history will remain but become outdated, while Circle wallet balances will stay intact. However, deposit addresses on Ethereum will be reset, rendering previous addresses non-functional, and the Testnet USDC contract will adopt a new address. Users are encouraged to switch to the Goerli Testnet for continued testing after Ropsten support ends on September 21, 2021.