Java and experience with custodial wallets + chains ( BTC, ETH, SOL, TRX)

Project is building an internal wallet technology platform for custodial operations across Bitcoin, Ethereum, Solana, and TRON. The platform will unify policy and governance, wallet management, transaction construction and execution, and signing coordination under a single client-owned stack, replacing the current fragmented model of multiple vendor-specific policy engines, wallet registries, and governance frameworks.