Senior Fullstack Engineer
📍 Hanoi, Vietnam
📞 +84 966 041 057
📧 haihv27@gmail.com
🔗 Portfolio · GitHub · LinkedIn
Senior Fullstack Engineer with 9+ years of experience building end-to-end web applications across frontend and backend. Expert in modern JavaScript/TypeScript ecosystem (React, Next.js, Node.js, NestJS), with experience in Golang, and proven ability to architect scalable systems, optimize performance, and deliver complete features from database to UI. Experienced in e-commerce, healthcare, Web3, and EdTech domains.
Frontend: Next.js, React, Nuxt.js, Vue.js, TypeScript, TailwindCSS, ChakraUI
Backend: Node.js, NestJS, Golang, Express.js, tRPC, Prisma, REST APIs, GraphQL
Database: PostgreSQL, MySQL, Redis, Database Design, Query Optimization
Testing: Playwright, Cypress, Jest, Vitest, Unit/Integration/E2E Testing
DevOps/Cloud: Docker, CI/CD, AWS, Kubernetes, Microservices Architecture, Kafka, Message Queue
Other: System Design, API Design, Performance Optimization, Agile/Scrum
E-commerce Platform: Architected and implemented full-stack e-commerce solution with scalable microservices backend (Node.js, NestJS), frontend storefronts (Nuxt.js), and admin portals, powering $4M/month dropshipping operations with optimized checkout flows and payment processing.
Healthcare SaaS: Built end-to-end infusion-center platform using T3 stack (Next.js, tRPC, Prisma), implementing FHIR-compliant APIs, database schemas for patient/scheduling data, and comprehensive frontend with feature flags and e2e testing.
Web3 Applications: Developed full-stack decentralized applications with Solana/EVM smart contract integrations, backend APIs (NestJS, Golang) for transaction processing and user management, and React frontends with wallet connections and real-time blockchain data.
valifetch: Type-safe HTTP client built on native fetch with Valibot schema validation, featuring automatic type inference, retry logic, and request/response hooks.
nestjs-solana-kit: NestJS integration for Solana @solana/kit v5.x, providing 12 production-ready services for account operations, transaction building, and WebSocket subscriptions.
Feb 2024 – Present — Moonraise – Blockchain and Web3 development on the Solana ecosystem
Worked directly with international clients from Korea, Singapore, and global markets to deliver Web3 solutions.
Developed full-stack dApps with Next.js/React frontends and NestJS/Golang backends, implementing complete features from API design to UI.
Built backend services handling transaction flows, user authentication, wallet management, and integration with Solana RPC nodes.
Designed and implemented RESTful APIs and database schemas (Prisma ORM) for user data, transaction history, and on-chain events.
Implemented Solana programs with Anchor, including smart contracts for randomness, prize pools, and SPL token operations.
Optimized backend performance with caching strategies (Redis), database query optimization, and efficient blockchain data fetching.
May 2023 – Jan 2024 — US healthcare startup – SaaS platform for infusion centers
Built full-stack features using T3 stack with type-safe API layer (tRPC), database modeling (Prisma), and Next.js frontend.
Designed database schemas for complex healthcare data (patients, appointments, treatments, medications) with proper relationships and constraints.
Implemented FHIR-compliant APIs for healthcare data exchange, ensuring proper validation and error handling.
Developed backend business logic for scheduling optimization, resource allocation, and notification systems.
Built frontend interfaces for data entry, visualization, and workflow management with real-time updates.
Integrated LaunchDarkly for feature management and deployed comprehensive Playwright e2e tests across the stack.
Apr 2022 – Mar 2023 — Crypto on-chain tracking and portfolio management application
Developed full-stack features for crypto portfolio tracking with React frontend and Node.js backend services.
Built backend APIs for blockchain data aggregation, caching strategies for on-chain data, and WebSocket connections for real-time updates.
Optimized database queries and indexing for fast portfolio calculations across multiple chains and wallets.
Implemented EVM chain integrations on both backend (Web3.js, Ethers.js) and frontend (wallet connections, transaction signing).
Designed and implemented caching layer (Redis) to reduce blockchain RPC calls and improve response times.
Apr 2021 – Mar 2022 — EdTech platform for creating, distributing, and consuming digital learning objects
Developed full-stack EdTech platform with React frontend and NestJS microservices backend.
Architected and implemented microservices for content management, user authentication, progress tracking, and analytics.
Designed database schemas for learning content, user progress, and assessment data with efficient querying patterns.
Built RESTful APIs with proper authentication (JWT), authorization, and input validation.
Implemented frontend features using design system components and integrated with backend APIs.
Set up CI/CD pipelines with GitHub Actions deploying to Kubernetes (EKS) with automated testing and rollback capabilities.
Sep 2020 – Mar 2021 — Shopify app development studio
Developed full-stack Shopify apps with Express.js/Node.js backends and React frontends integrated with Shopify APIs.
Implemented OAuth flows, webhook handlers, and background job processing for Shopify data synchronization.
Built Freshdesk integration with backend services handling webhook events, data transformation, and API communication.
Designed database schemas for app data storage and implemented efficient querying for merchant dashboards.
Jan 2018 – Aug 2020 — E-commerce solutions company focused on checkout and dropshipping
Developed full-stack e-commerce platform serving $4M monthly revenue, including checkout flows, payment processing, and order management.
Built microservices backend with Node.js/Express.js handling payments, inventory, order processing, and third-party integrations.
Implemented frontend storefronts (Nuxt.js with SSR) and admin dashboards (Vue.js) with real-time data synchronization.
Designed database schemas for products, orders, customers, and payments with complex relationships and transaction handling.
Optimized backend performance through caching, database indexing, query optimization, and asynchronous processing.
Integrated payment gateways, shipping APIs, and fulfillment services with proper error handling and retry logic.
Introduced Cypress e2e testing covering critical user flows from frontend to backend.
Feb 2017 – Dec 2017 — Shopify app development startup
Developed full-stack Shopify apps using Express.js backends and Vue.js frontends.
Built backend services with Shopify API integrations, webhook processing, and event tracking systems.
Implemented data processing pipelines using Kafka for scalable analytics and reporting features.
Deployed and managed applications on AWS (EC2, RDS, S3) with monitoring and logging.
Completed all IT courses at Hanoi University of Science and Technology
Vietnam Mathematical Olympiad Award — Hung Yen Specialized High School