Worked on stabilizing staking batch processing in the xuelongqy/wallet-core repository by addressing a critical bug affecting transaction encoding for staking actions. Focused on correcting the custom call indices for BondAndNominate and ChillAndUnbond operations, the work involved updating Protocol Buffers definitions and refining C++ encoding logic to ensure accurate handling of custom indices. This fix eliminated a latent issue that previously risked mis-encoded transactions, thereby improving the reliability of staking batch submissions. Leveraged expertise in Polkadot, Protocol Buffers, and transaction encoding to deliver a targeted solution that reduced the potential for user-facing errors in staking workflows.