davidmei

I'm a full-stack blockchain engineer who builds and runs production crypto platforms end to end. I built KCWPay (kcwpay.com) on my own: a live custodial wallet and exchange with a merchant payment gateway. It handles multi-chain deposits and withdrawals (BTC, ETH/EVM, BNB, TRON/TRC-20, Solana, TON, XRP and more), swaps, merchant payments, payouts and settlements, an isolated transaction signer, proof of reserves, and Telegram/Discord payment bots, plus a full admin and risk back office. The stack is Python/FastAPI, React, PostgreSQL, Redis and Docker, with 170k+ lines of code and 296 test files.

I'm looking for remote freelance, contract or part-time work on crypto payment gateways, wallets and exchanges, exchange-script customisation, Telegram bots, or security reviews of custody and withdrawal systems. Security and correctness come first in everything I build.