Natthawat
Narin

Digital lending platforms for a leading Thai commercial bank and a new virtual bank — billing, reminders, and repayment at national bank scale.

• Built 30+ RESTful API endpoints in Go (Gin, Bun, PostgreSQL, AWS S3, Redis, Gotenberg) for bill generation, reminder, and repayment flows.
• Built 14+ Kafka consumers processing billing and repayment events asynchronously.
• Built 4 Airflow DAGs scheduling recurring bill reminder jobs, with AWS S3 for document storage.
• Wrote unit and integration tests, holding coverage above 80%.
• Built regulatory reporting pipelines as 10 AWS Glue jobs in Python using Spark SQL.
• Load-tested APIs and Kafka consumers with k6 against WireMock-stubbed dependencies — profiling TPS, CPU, memory, and database behavior to remove bottlenecks and support 20k–100k users.

• Go
• Gin
• Kafka
• PostgreSQL
• Redis
• Airflow
• AWS Glue
• Spark SQL
• k6

Sole developer — backend, web, and mobile through to deployment.

• TX-Service Laos — payment gateway for the Lao market with QR deposits and bank withdrawals across 35+ RESTful endpoints in Go (Gin, PostgreSQL, Redis), with RFC 9421 (Ed25519) webhook verification, SQS FIFO event processing, and a Next.js admin dashboard.
• Smart Hire AI — hiring platform where candidates answer interview questions and the ChatGPT API analyzes their responses; built in Next.js (MongoDB) and Tailwind CSS, running server-side logic in the app itself rather than a separate API service for faster delivery.
• North HR — employee management across a Flutter mobile app, a Next.js back-office, and a NestJS API (Prisma, PostgreSQL) exposing 50+ endpoints: location-based check-in/out via Google Maps API, push notifications through Firebase Cloud Messaging, and S3 file storage with e-signed documents viewable by link.
• GiftMe — donation platform for streamers with SCB bank QR payment integration, built in Next.js with a NestJS backend (MongoDB) exposing 40+ endpoints.
• 5v5 Laos — landing page for a Lao e-commerce marketplace, built in Next.js and Tailwind CSS, localized in Thai, Lao, and English, and responsive across every device.
• Deployed all self-hosted apps with Docker behind Nginx Proxy Manager, delivered by GitHub Actions to AWS, DigitalOcean, or Firebase App Distribution.

• Go
• NestJS
• Next.js
• Flutter
• PostgreSQL
• MongoDB
• AWS SQS
• Docker
• GitHub Actions

Xspring Digital — a crypto trading and ICO portal on web, iOS, and Android.

• Migrated the system from monolith to microservices, building RESTful services in Node.js (Fastify) and Go (Fiber) with Redis caching and RabbitMQ for ledger balance updates.
• Built the trade, KYC, notification, and back-office UIs in Nuxt.js (Sass) and Flutter.
• Integrated external providers — AppMan and NDID for KYC, Coinbase for trading, and Fireblocks for the cold wallet dashboard.
• Built a public trading API documented with OpenAPI for programmatic access.
• Wrote Kubernetes manifests (Deployment, Service, ConfigMap) to deploy each new service.
• Mentored junior developers, improving code quality and maintainability.

• Go
• Fiber
• Node.js
• Fastify
• Nuxt.js
• Flutter
• RabbitMQ
• Redis
• Kubernetes

Thinker Loan — home and personal loan platform for a Thai commercial bank.

• Built RESTful microservices in Go (net/http) backed by MongoDB, exposed through GraphQL with gRPC.
• Built a real-time chat system in the Next.js web app over WebSocket.

• Go
• GraphQL
• gRPC
• MongoDB
• Next.js
• WebSocket

Car rental platform for the Provincial Electricity Authority (PEA).

• Built the site in Next.js with a Node.js (Express) API backed by PostgreSQL.

• Next.js
• Node.js
• Express
• PostgreSQL