WANCHAI NUPINIT

Senior Software Engineer
email [email protected]
phone 087-271-3536
location Bangkok, Thailand
linkedin linkedin.com/in/chai-wanchai

Professional Summary

Senior Software Engineer with 6+ years building production-grade systems across FinTech, energy, and enterprise — from zero to scaled. At Bitkub (Thailand's #1 crypto exchange), architected and owns the Crypto Wallet backend: deposit/withdrawal pipelines handling millions of transactions with 99.5%+ uptime and zero critical security incidents. Delivered FIDO2/WebAuthn passkey withdrawal, fraud detection (mule account scoring, transaction monitoring), and re-architected the Etax system — cutting processing time 50% and saving $300/month in infra costs. Previously built enterprise platforms at SCG and microservices at PTT Digital. Awarded Rising Stars 2025 and Best Delivery Team 2024; 100% goal achievement across all 3 review cycles. Thrives in high-ownership backend roles: Golang microservices, Kubernetes (EKS/GKE), security-first design, and DevOps-integrated delivery.

Work Experience

Senior Software Engineer – Crypto Wallet Team
Jan 2022 – Present
Bitkub Online Co., Ltd | Bangkok, Thailand
Led Crypto Wallet infrastructure for millions of users with 99.5%+ uptime
Built Passkey Withdrawal (FIDO2/WebAuthn) replacing SMS OTP, zero security incidents
Re-architected Etax system: 5–6 hrs → 2–3 hrs (~50% faster) and saved $300/month
100% goal achievement (2022–2024) & Best Delivery Team 2024
  • Developed fraud prevention systems, transaction monitoring, mule account detection.
  • Automated coin listing pipeline, NCR whitelist, coin recovery, airdrop & compensation APIs.
  • Redesigned withdrawal service from PHP to Golang microservice; reduced customer bugs >50%.
  • Built SupMidMan AI (LLM) for support triage; won Rising Stars Award (2025).
  • Deployed on EKS Graviton with ArgoCD, OpenTelemetry; security-first with Vault & KMS.
  • Maintained 80%+ unit test coverage and strong documentation standards.
Full Stack Developer
Aug 2021 – Dec 2021
PTT Digital Solutions Co., Ltd | Bangkok, Thailand
  • Developed microservices for PTT station operations — real-time notifications, monitoring tools, and POS system.
  • Built real-time notification service for station events and alerts.
  • Integrated POS system APIs for transaction processing at PTT stations.
Stack: Node.js, ReactJS, MongoDB, REST API, SQL
Full Stack Developer
Nov 2019 – Jun 2021
The Siam Cement Public Co., Ltd (SCG) | Bangkok, Thailand
Enterprise web apps (retail, finance, reporting)
Document gen (quotation, PO, invoice) via jsreport
Sales reporting + FTP→GCS automation
Workspace booking & permission management
  • Designed and built full-stack enterprise platforms for SCG's retail network — covering product management, inventory, payment, and permission systems.
  • Developed document generation service (quotation, PO, invoice, receipt) using jsreport with PDF/Excel export via Node.js API.
  • Built sales reporting system with PostgreSQL schema design, FTP-to-GCS automation pipeline, and a workspace booking system with floor plan management.
  • Wrote Swagger API specs, stored procedures in MS SQL, and connected multiple microservice backends to React/Next.js frontends.
Stack: ReactJS, NextJS, Node.js, PostgreSQL, MS SQL Server, jsreport, Docker, GCS.
Backend Developer
Jan 2019 – Oct 2019
Magicbox Asia Co. | Bangkok, Thailand
  • REST APIs for SCBlife mobile app; automated testing & CI/CD; monitored performance with ELK Stack.
Software Engineer & Trainee
Jan 2018 – Dec 2018
Thomson Reuters Co., Ltd | Bangkok, Thailand
  • Built testing scripts, REST APIs, web services, and performance dashboards; ETL pipeline to Elasticsearch.
  • Generated metric reports from Graphite time-series data; built Grafana dashboards for customer monitoring.