According to TechFlow, on November 25, according to official news, the core infrastructure of STRK staking has been deployed to the Starknet mainnet.

The Validator tool is now in use. Users who hold at least 20,000 STRK tokens and run a full node can become a Validator; the UI and DApp for Delegators will be launched when the official release is released tomorrow. Any user holding STRK can participate in staking by delegating tokens to a Validator.