Pham Van D.

I build production backend systems and blockchain infrastructure: Go/Node.js APIs, Solidity smart contracts, Cosmos SDK chains, indexers and payment flows. 4 years shipping at AIOZ Network and Dwarves Foundation. WHAT I CAN HELP YOU WITH Backend & APIs for web products - REST/gRPC APIs and services in Go and Node.js/TypeScript - PostgreSQL / MongoDB data modeling, Redis caching, RabbitMQ queues, deployed on GCP - Performance fixes: cursor pagination, connection pooling, background jobs Smart contracts & EVM - Solidity contracts: stablecoin (USDC FiatTokenV2) deployment, upgradeable contracts with multisig control - EIP-712 / EIP-1271 signatures, Permit2, CREATE2 deterministic deployments - Wallet and payment flows, including x402 payments Blockchain infrastructure - Cosmos SDK / Ethermint chains: staking, IBC modules, chain upgrades - Chainlink nodes and OCR data feeds: setup, operations, troubleshooting - Custom indexers over direct RPC (e.g. DEX swap tracking on BSC), no third-party APIs - Bitcoin / Lightning nodes on low-power hardware, AI wallet agents SELECTED WORK - AIOZ Network (Cosmos SDK L1): backend and chain services for interoperability, payments, identity, data feeds and indexing. [add 1 number] - Lufina (RWA tokenization): backend for a real-estate tokenization platform. [add what you built] - Dwarves Foundation: 2.5 years building backend systems for client products. [add 1 highlight] HOW I WORK - Written updates you can read in 2 minutes, replies within a few hours - Tests and docs included, so your team can maintain the code after handoff - I raise risks and trade-offs early instead of after the deadline Stack: Go, Node.js, TypeScript, Bun, Solidity, Cosmos SDK, Chainlink, PostgreSQL, MongoDB, Redis, RabbitMQ, GCP Send me your project goal and current stack. I'll reply with a short technical plan and an estimate.