Developed cross-chain wallet profiling capabilities for the x402 wallet analytics product, focusing on backend and API development using JSON. Built and deployed the WalletIQ wallet intelligence API within the coinbase/x402 repository, enabling comprehensive EVM wallet profiles that include age, activity metrics, DeFi usage, and risk scores across five or more chains. Designed a REST endpoint to deliver complete wallet profiles in a single call, supporting data-driven risk assessment for EVM addresses. Enhanced internal documentation and onboarding processes to streamline integration of WalletIQ and facilitate cross-chain analytics. The work emphasized scalable architecture and traceable, maintainable code for future extensibility.