Hendry Zheng

Backend, API Gateway & Web3 Enthusiast — Remote Worldwide

I design, migrate, and optimize API platforms and software systems for fintech and SaaS. My focus is on practical, reliable engineering — from backend infrastructure to complete app ecosystems.

GitHub • LinkedIn • Website • Portfolio • Gateway Showcase

Core Expertise

• API Gateway design & migration (KrakenD, Tyk, Kong)
• API modernization & OpenAPI standardization
• Node.js / TypeScript / PHP backend optimization
• Distributed system reliability & chaos testing
• Mobile App Development (React Native / Ionic)
• Web App Development (Next.js / Laravel / Vue)
• Secure API design (JWT, signed payloads, rate limiting)
• Process automation & workflow orchestration
• Financial systems & loan processing workflows
• Third-party API integration & data synchronization
• Web3 & DeFi protocol integration (ethers.js, smart contract automation)
• ETL pipelines & data transformation
• Business process digitization & legacy system modernization
• Event-driven architecture & message queuing (RabbitMQ, Kafka)
• Disaster Recovery (Tyk, PostgreSQL, Redis)

Service Offerings

Microservices Setup

Build or migrate your systems into scalable, maintainable microservices — with clear APIs, automated deployment, and monitoring built-in.

API Gateway Audit

~2 weeks — Assessment report + recommendations

Migration / Setup

Hands-on migration to KrakenD / Tyk — Delivery + docs

Mobile App Development

Cross-platform (iOS & Android) app design and development using React Native / Ionic

Web App Development

Full-stack web development with modern frameworks (Next.js, Laravel, Vue)

Web3 & DeFi Engineering

EVM smart contract integration, ethers.js automation, and on-chain monitoring for lending, staking, and liquidation flows

Digitalise Manual Operations into Automation Engineering

Transform manual processes into automated systems with streamlined workflows and reduced human error

Loan Management System

End-to-end loan processing systems with application tracking, approval workflows, and payment management

Backend End-to-End Integration

Complete backend system integration connecting multiple services, databases, and third-party APIs

Reliability & DR

HA & DR design, monitoring, and validation

Web3 / DeFi Focus

Hands-on DeFi engineering with ethers.js for lending, liquidation, and execution tooling. Designed for reliability-first operations with clear monitoring and alerting.

Ethers.js Tooling

Wallet orchestration, multicall batching, and transaction hygiene (gas controls, retries, health checks).

Protocol Integrations

EVM-compatible lending, staking, liquidation, and portfolio monitoring pipelines with alerting hooks.

Venus Liquidator Monitoring (Project)

Ethers.js-driven watcher for on-chain positions with liquidation visibility and alerting hooks.

Fullstack Node/TypeScript Builds

End-to-end Node/Express and React/TypeScript apps for auctions, workflow ops, fares, and service health.

Auction System (Node/Express + React TS) — Real-time bidding flow with TypeScript, API orchestration, and reactive UI.
Task Application (Node + React) — Task orchestration app with Node backend and React frontend.
Trip Fare Application — Fare calculation workflow with backend services and client UI.
simple-nodejs-httpstat — Lightweight HTTP latency/status probe for service health checks.

Highlighted Engagements

Venus Liquidator Monitoring — DeFi liquidation watcher built with ethers.js, alerting, and on-chain risk visibility.
Fintech Gateway Migration — Migrated from custom Express gateway to KrakenD; improved scalability and observability.
Network Operations API (CSET) — Modernized legacy APIs for gateway onboarding and network analytics.
Customer Self-Service Platform (BSS) — Unified multiple customer APIs under a single API gateway for better user experience.
Disaster Recovery (Tyk Ecosystem) — Architected DR for gateway, dashboard, pump, and portal.
Gateway Proxy Release Testing — Designed percentage-based traffic rollout strategies and test plans.
Velintech Client Apps — Delivered end-to-end mobile & web app solutions for SMEs and enterprises.

Engagement Model

Project-based or short-term consulting. Remote collaboration preferred. Optional retainer for maintenance.

Pricing: Get quote for project or hourly rates

Contact

Prefer email for initial contact. I respond to concise project descriptions (scope, timeline, and preferred collaboration model).

Contact via Email