Hoang Dang Tan Phat - Senior Software Engineer | Full-Stack

Professional Summary

Full-stack engineer with nearly 9 years of experience (since Jun 2017), shipping production features end-to-end from React / Next.js / TypeScript frontends to 6+ years of Golang backend (since Sep 2019) — microservices, gRPC services, and event-driven pipelines. Take full ownership of features — from technical design and implementation to CI/CD release, observability, and performance tuning on AWS / GCP. Have shipped real workloads in Web3 / DeFi (cross-chain trading, on-chain indexing) and Applied AI / LLM (LangGraph + RAG support agent). Strong on distributed systems, code quality, automated testing, and developer experience — used to working in Agile, cross-functional teams across time zones.

Technical Skills

Primary Backend

Other Backend Languages

Node.js / TypeScript (4 yr) | NestJS | Python (1 yr) | FastAPI

Frontend

Architecture & Patterns

Databases & Search

PostgreSQL | MongoDB | Redis | Elasticsearch | pgvector

Messaging & Streaming

Kafka | NATS JetStream | Debezium CDC | gRPC | WebSocket

Cloud & DevOps

Observability & Quality

Web3 & Blockchain

Domains Delivered

Web3 / DeFi (3 yr — Bitcoin PSBT, EVM, Solana, cross-chain) | Applied AI / LLM (1 yr — LangGraph, RAG, Claude API) | E-commerce | FinTech

Professional Experience

Caliber Venture (member of KyberNetwork)

Aug 2023 – Present

Optimex — Decentralized Cross-Chain Trading Platform (Apr 2024 – Present)

Position: Backend Lead

Owned end-to-end delivery of Golang and Node.js/NestJS microservices with React frontend, serving 2,000+ users and processing $4.9M+ trading volume across 2,247+ cross-chain transactions
Built core trading services in Golang — order routing, on-chain event indexer with reorg handling, and worker pools using goroutines + channels for concurrent transaction processing
Designed cross-chain order routing engine aggregating liquidity across Bitcoin (PSBT/Taproot), EVM (Ethereum, Arbitrum, Base), and Solana — 100+ daily transactions
Built the dApp frontend in React / Next.js — wallet connections (MetaMask, WalletConnect) and on-chain contract calls via ethers.js / wagmi / viem; wrote Solidity ERC-20 mocks for integration tests
Built on-chain event indexer in Go monitoring contract events (swaps, liquidations, position changes) with real-time WebSocket push, missed-block recovery, and a GraphQL API (The Graph subgraphs) for clients
Set up cloud-native infrastructure on AWS / GCP with ArgoCD + Kubernetes, achieving 99.5% uptime; configured Datadog from scratch (APM, RUM, log pipelines, dashboards & alerts)
Reduced API response times by 60% via Redis caching and PostgreSQL query optimization; established CI/CD with GitHub Actions and automated test gates
Drove a strong testing culture — unit + integration tests with Testcontainers (real Postgres / Redis / Kafka in CI), mockery for Go interface mocks, and Jest / Vitest for Node.js / TypeScript services; e2e tests using Cucumber (BDD) + Playwright; maintained ≥ 95% coverage on critical services
Shipped a customer-facing LLM support agent (LangGraph + simple RAG, pgvector, Claude API) integrated with the core platform via internal APIs

Tobi — Web3 Telegram Mini App Wallet (Aug 2023 – Apr 2024)

Position: Software Engineer

Built Golang and Node.js/NestJS microservices with React Telegram Mini App frontend, serving 8,000+ users for multi-chain wallet management
Integrated Kafka event streaming processing 5,000+ on-chain events/day with guaranteed delivery and idempotent consumers in Go
Implemented Debezium CDC for real-time wallet state sync, reducing latency to sub-second

OnPoint Ecommerce

Aug 2020 – Jul 2023

Hermes — Multi-channel Chat SaaS Platform (Jan 2021 – Jul 2023)

Position: Key Developer (Golang)

Architected and implemented Golang microservices with gRPC handling 500,000+ messages/month across Lazada, Shopee, Facebook, and Zalo, achieving <100ms response time
Built NATS JetStream pipeline in Go processing 20,000+ events/hour with at-least-once delivery and dead-letter handling
Developed Auto-Reply system reducing customer response time by 60%; full unit + integration test coverage on critical paths
Operated services on AWS with Kubernetes; established alerting and dashboards for on-call rotation

Opollo — SWAT 2 (CRM & E-commerce Platform) (Aug 2020 – Jul 2023)

Position: Team Lead

Led team of 8 developers delivering full-stack platform handling 50,000+ orders/month
Built backend services in Golang and Node.js for concurrent order processing with goroutines + worker pools; integrated 3 payment gateways (VNPay, Momo, ZaloPay) processing 20,000+ transactions/month
Implemented Elasticsearch + Kibana for product search and operational analytics dashboards

NUS Technology

Jun 2017 – Jul 2020

Whalesave — Financial Management Platform (Jan 2019 – Jul 2020)

Position: Team Lead

Led team of 5 developers through complete product lifecycle from concept to production launch
Built Express.js backend with MongoDB handling 10K+ requests/day; integrated Stripe, Rapyd, PayPal processing 1,000+ payments/month

Welligence — Data Analytics Platform for Oil & Gas (Jun 2017 – Jul 2020)

Position: Software Engineer

Worked with distributed team of 5 developers across Vietnam and US time zones in Agile cadence
Implemented Elasticsearch full-text search indexing 500K+ records with sub-second response
Built database sharding strategy supporting 5x data growth without performance degradation

Side Projects

Glow — AI-Powered E-commerce with LLM Customer Support

Personal full-stack project: skincare e-commerce site with an AI chat assistant — Next.js frontend, Python AI service, Stripe payments.

LangGraph workflow routing intents (order lookup, product search, FAQ retrieval) with human-handoff fallback
Simple RAG using Voyage AI embeddings + pgvector for product & support FAQ answers
Stripe payments + admin dashboard, real-time chat via Pusher + Next.js

Ditto — PostgreSQL CDC Service in Go

Open-source Go service implementing transactional messaging for event-driven architectures — captures PostgreSQL changes via logical decoding (WAL / pgoutput) and publishes to Redis with at-least-once guarantees.

Logical replication consumer in Go — filters WAL events and maps them to configurable Redis topics
Auto-sync publications — supports single-publication and per-table publication strategies, YAML-driven config
At-least-once delivery with structured event payload (ID, schema, table, action, data, data_old, event_time)

Tech: Go | PostgreSQL (logical decoding, pgoutput) | Redis | Docker | CI/CD

Key Achievements & Impact

          Golang Engineering
          
              Built Go microservices with gRPC serving 500K+ messages/month at
              <100ms latency
            
              Implemented NATS JetStream & Kafka consumers in
              Go with idempotency and DLQ
            
              Built on-chain indexer in Go with reorg handling and missed-block
              recovery
            
              Strong test discipline — unit + integration tests on critical paths, table-driven
              tests

          Cloud & DevOps
          
              Operated cloud-native apps on AWS & GCP with Kubernetes + ArgoCD
            
Achieved 99.5% uptime serving 2,000+ concurrent users

              Configured Datadog from scratch (APM, RUM, logs, dashboards, alerts)
            
              Established CI/CD pipelines with automated tests and security scans

          Full-Stack & Delivery
          
              Shipped full-stack features end-to-end across React / Next.js + Go / NestJS backends
            
              Delivered 6+ production systems from concept through launch and
              scaling
            
Reduced API latency by 60% via caching and query optimization

              Cut incident response time by 70% with monitoring & alerting

          Leadership & Collaboration
          
              Led engineering teams of 5–8 developers across Vietnam & US time
              zones
            
              Worked in Agile cadence with cross-functional product, design, and ops stakeholders
            
Mentored juniors, ran code reviews, established team coding standards

              Comfortable communicating in English with global, distributed teams

Education & Languages

VNUHCM — University of Information Technology

Bachelor of Software Engineering | GPA: 7.9/10 | Vietnamese (Native) · English (Professional Working)

2014 – 2019